i'm a sonar 8.5 user and i'm working with another producer who uses x3. he asked that i save my project as a .cwb and send. he contacted me recently and stated there were several tracks that didn't seem to belong where they should be; i.e., a kick drum and a vocal track had somehow morphed into one track, and other similar oddities. i went back to my computer, loaded the .cwb and indeed found tracks playing that had previously been muted and things that were out of place. i then re-loaded the .cwp of the mix i'd done myself, and things were peachy.
 
am i missing a step with respect to saving bundle files? i've never had a reason to use them, since i backup to an external drive, but i plan on working with this producer and apparently he's been successful with bundles, so it'd be a help all the way around.
 
please advise.

Bundle files have not work well for most folks around here for a long time, Use CWP for best results. 
 
To transfer files I make a master folder for the Album
In that folder is a folder for each song
In each Song folder is the CWP and the associated audio file folder. 
Just drag and drop the Album folder to a external drive. Done. 
 
You sound like you already know how to back up properly. He just asked for the wrong format which makes me wonder how well he understands Sonar. 

Just save the project and send it. You might have to zip it if there are multiple files....  I have used the method Cactus uses and it works fine.
 
I have successfully used BUN files but I have also had problems with them. I have sent normally saved project files successfully.
 
When collaborating, I use MP3 as a working medium and send them with email.... then I send the tracks to the recipient as waves once they are all to his/her liking.
 
Some of the free services will let you send multiple wave files in a package. The other person simply drags them into a new project set up with the same BPM tempo..... Of course, if you're wanting all the FX and things, the CWP or BUN file is the way to go to duplicate the settings...assuming the other persona has the same exact plugs and VST's... if not, all bets are off.

I find that these days having 2 backups is still not enough ,
so I triple stack on the back of my tracks.

Yea, bun files are iffy.

> Bundle files have not work well for most folks around here for a long time, Use CWP for best results. 
 
Another one I would like to see fixed with X3D or X3E. If anybody has any steps to repro this issue?