I guess I should open this with "send your stuff to a professional" along with a wad of cash and a prayer they do it right.
 
However, if you are like me and have limited resources (having to pay out $1000/mo for health insurance ... ouch), and you have the Producer version and/or you have purchased a plug-in like Izotope Ozone ... you have the tools to attempt Mastering.  Assume that one bright day someone actually wants to give you money for your songs, some of which are a few years old, and you decide that with the new Sonar, new plug-ins, coupled with your ever-increasing experience recording ... to go back over your songs and fix them, prior to submitting them.   So you open the .bun files and the old mixes, and things are missing, things don't load, the master mix is gone, and basically you are screwed because you are an idiot.  The end result being you have to spend 3 weeks 14hrs a day fixing stuff.  Bummer.  This sucked BIG TIME.  I cannot express what a shocker this was.  I thought I backed everything up.  I am a backup nut.  So here is how to avoid future pain and misery, and save a whole bunch of time:
 
1.  Set up a Master Bus, and route everything through the Master on its way to your audio card.  When you press Mute on the Master Bus, there should be NO sound.  Modify your normal.template so that every new project you start is set up this way.  Why?  Because when you want to master your mix, you simply stick your plug-ins into the Effects box on the Master Bus.  If you need to change something in the mix, simply go change it, and you can A-B the master/un-mastered mix ... easily.  Or ... you can do it the way I wound up doing it ... er, was forced to do it ... and mess around with a bounced down or exported mix and wind up wasting a tremendous amount of time processing and re-processing tracks even with a quad-core CPU running at 3.2ghz.  I will never ever record anything ever again without setting my Projects up routed through a Master Bus.
 
2.  Before you 'leave' a mix and move on to bigger and better things ... BOUNCE ALL THE SYNTHS TO THEIR OWN AUDIO TRACK!  Bounce all the midi down too.  Otherwise you may one day be using Sonar X27, and open up that mix you made in Pro Audio 5, and it will be a complete bag of doo doo.  The synths won't load either because you don't have them anymore, or the new Sonar doesn't recognize them properly, or that patch you tweaked so carefully ... well its GONE.  Boo hoo.  A penny saved is a penny you don't have to dig to China to retrieve. 
 
3.  Now because you have used a Master Bus, and you have bounced down all the stuff that might disappear one shocking day ... hooray ... when you export the entire mix as a .bun file, and burn that to a DVD in a velvet box ... everything you need to re-create and re-master the mix ... well, its all there.  No sweat.  No tears.  No drinking yourself blind and gaining 10 pounds in the process trying to figure out what you did 7 or even 10 years ago.
 
That's my story, and I'm sticking to it.

Good post! Good advice! I also had some huge problems when I had to use some old projects of mine last year...
 
Two things:
 
1. do you bounce everything with the effects included...? Because those effects may be gone too with X27... Or do you only bounce synths without the effects? And what about audio tracks: do you bounce them with effects too? Just curious.
 
2. I personally never save finished projects as a bun file but as an open (simple CW project) file: I don't know if there is a way to 'unzip' bun files but when you save an open all the audio will be saved along with (providing you ticked the right options) it so you can even simply load, if S27 doesn't make it, the audiotracks straight into Cubase 24 or Pro Tools 29.

I've been pondering how to archive things in a way that avoids some of the issues you've mentioned. I figure what I'll probably do...
 
Create a folder for all exports so I have easy access to all the different files.
 
Usual stereo mixdown at 24 bits and whatever samplerate the project was recorded/mixed at. This will have some headroom left on the Master bus and be saved. It can then be available for sending off to a mastering house. It will also be tossed into a new project for me to master myself and that project would get exported to 16bit 44.1khz for my own personal use.
 
Bus export with effects. Again with some headroom left and it could be used for stem style mastering. I might also export another without effects... maybe.
 
Track export with effects and level/pan settings. All tracks exported with effects so if I want to do a volume remix, add or replace tracks or create a mashup I can without remixing. This also avoids issues like missing plugs or synths because they'll be right on the tracks.
 
Track export without effects or level/pan settings. This way I have just the raw audio. It wouldn't be mixed per se but I would make it so all the levels are nice and clear kind of like how you would capture things while recording. Then I could start completely from scratch if I wanted starting with good strong signals. I started working on an old album of mine a while back and was fortunate enough to have just the raw audio. I'd like to be able to go back to anything I create in this manner.
 
This all might take up a lot of disk space but I've lost some stuff to guys not archiving things and it was really upsetting.

The more things you do the better; however, if you don't save the project as a bun file, the audio files that are somewhere in one of your potentially many /audio folders WILL NOT BE SAVED.  The .cwp files only --point-- to the .wav files in whatever audio folder they are in. 
 
As to the Export Tracks suggestion, you are still going to have to tell the .cwp where all those files are if you re-open it on a different setup. 
 
I still kinda think that saving the whole thing as a bundle (cwb file) and then burning those bundles to dvd is the way to go.  If Roland goes belly up, or my system takes a dump, I still have the Sonar install disks, and can re-install, open the bundle, export the waves, and pull the wavs into Supersonar or whatever.  If I open the bundle it will automatically create a new .cwp file which will reference all the wavs.  Plus, that is what Cakewalk recommends in their documentation.
 
But then what if the bundle file gets a scratch on the backup disk?  So I think, after ruminating the above posts, that the best thing to do is to:
 
1.  Save-as the .cwp with the bounced synths to a new folder, which will copy all the raw wave files into that new folder
2.  export all the tracks WITH EFFECTS to that folder (in case the effects/plugins go missing)
2.  save the whole thing as a cwb file to same folder (which in most cases will be easiest way to get back the original project)
4.  burn the folder [containing ONE song] to 2 separate DVDs with verify on after write
5.  put those DVDs in their own labeled jewel cases, keeping one on site, and the other off-site
 
The reasoning behind one song per backup is that if the DVD gets damaged, and they do get damaged, you only lose one song, not a bunch.

Timeking
The more things you do the better; however, if you don't save the project as a bun file, the audio files that are somewhere in one of your potentially many /audio folders WILL NOT BE SAVED.  The .cwp files only --point-- to the .wav files in whatever audio folder they are in. 
 

Per-project folders save audio for the project in a single directory directly underneath the cwp. Bun files were rendered redundant when per-project folders were introduced years ago. If one failed to properly create a per-project folder for a project, a simple "Save As" with "Copy all audio with project" checked and proper path names in the Project and Audio path entries will fix the problem.

I meant export them as waves so they'll open in anything I want. I don't like screwing around with all these proprietary file formats or OMF bullpuckey. A wave is wave is a wave.
 
I'd still save some bundles and/or project files with the audio copied to folder for more immediate tweaks but that other stuff is pretty much fool proof. I've learned my lesson after having to switch platforms once already. I'm just thankful I was able to export the original waves for my old album from the old system. OMF did not work at all when importing into Sonar and there is no way it would tolerate an ancient Nuendo project file.

scook

Timeking
The more things you do the better; however, if you don't save the project as a bun file, the audio files that are somewhere in one of your potentially many /audio folders WILL NOT BE SAVED.  The .cwp files only --point-- to the .wav files in whatever audio folder they are in. 
 

Per-project folders save audio for the project in a single directory directly underneath the cwp. Bun files were rendered redundant when per-project folders were introduced years ago. If one failed to properly create a per-project folder for a project, a simple "Save As" with "Copy all audio with project" checked and proper path names in the Project and Audio path entries will fix the problem.

I really gotta learn more about this. Mainly how to point it all exactly where I want it which for archiving is usually my desktop so I can toss it on an external drive or disc. I'm sure it's simple enough though. The bundles just go in a neat little package without worry but i know they are unreliable. I'm sure the Per Project Folders could work in the same way but I just haven't attempted that type of save yet.

The paths are at the bottom of the Save As dialog. Change the project patch and the audio path should change automatically to an Audio directory under the specified project path.

Timeking
The more things you do the better; however, if you don't save the project as a bun file, the audio files that are somewhere in one of your potentially many /audio folders WILL NOT BE SAVED.  The .cwp files only --point-- to the .wav files in whatever audio folder they are in. 
 
<...>
 
1.  Save-as the .cwp with the bounced synths to a new folder, which will copy all the raw wave files into that new folder
<...>
 

 
Aren't you contradicting yourself here...? Anyway, like scook said: no need for buns anymore. Whenever I finish a project (and I mean REALLY finished it), I save it as a new one with the 'Copy all audio with project' option enabled. Works like a charm. Gets rid of all the junk wavs too in one go.

that's a great way to do it, but if you ever decide to change daws, you may have issues eventually.  the CDs I produced 10 years ago I did with early version daws and vsts, and now i'm hosed if i wanted to recreate them... very similar to the techniques you talked about, now I would render un-mastered stems to a folder for each song.  Stem content is a subjective issue, depending on who you ask, but my stems group similar items into a stem track, so instead of 30 tracks, I would have maybe 10 stem tracks for a song. Of course, my intent of the stems are to allow a mastering engineer to recreate the song.
so my old songs will be re-built using better skills, newer tech, better quality vsts, etc... it's just hard spending the time to do it... and they aren't the same as the old stuff I posted on iTunes, but I'm glad I'm redoing them so I can now have a 'Best of...' 'remastered and revised' version.