I'm running Sonar X3e and maybe there's a better way to go about this, but here's how I had to go about adding new takes (via Take Lanes) to an existing track with extensive comping edits.
 
My audio track had about 20 Take Lanes with comping edits and I recorded more material and added more take lanes. On the first pass I noticed that all of my comping edits had been "overruled" by the new material, as the newest Take Lane is active or unmuted after it is recorded, (and this behavior is as expected as per how Take Lanes work). To reclaim my old comping edits I saved the results as another project and then reopened the original project with my old edits in tack. I then locked all of my old Take Lanes and cut and pasted the new take lanes into a new track from where I dragged the new Take Lanes into the old track with all the old comping edits. All of the old comping edit sections (measures and portions of measures) which spanned all of the old Take Lanes did not show up on the new Take Lanes once they were displayed with all of the old Take Lanes. As I comped and edited to blend in the new Take Lanes I noticed some strange behaviors, and looked up at one point to notice that my old clip selections from my old comping edits were missing for a large portion of the track.
 
I suppose that Take Lanes are not (yet?) designed to do what I'm trying to do with them. When they work well I really like them, but it feels like I have to really be careful and Save my file often to move forward on my project. 

I keep a Sonar notebook.  One entry starts out with the warning "MULTIPLE COMPS ON ONE TRACK ARE DANGEROUS", to make sure that I NEVER do what I did again.  Like the lady that backed into the airplane propeller, it dis-assed-her.
 
My 'safe' methodology is to NOT do a comp on a track that is part of the mix, but instead to insert a blank track and do ONE comping/recording on that track, flatten it, take the lock off, bounce to clip, and then drag/copy that clip to my "real track", where "real" is defined as the track belonging to the mix.  I then archive that comp track. 
 
If the "real track/part of the mix" requires multiple comps, I insert another blank track, do the same shtick, and drag/copy the bounced comp into my mix track.  My mix track becomes an assembly of clips that were created by comping them on their own tracks.  Since I've archived my comp-tracks, I can go back to them if I want.

How about locking the position and data of all the clips in the track (by selecting them and hitting Ctrl+K) after you did comp edits and then recording additional takes to the same track? Would that work?  

Thanks for the info!
 

My 'safe' methodology is to NOT do a comp on a track that is part of the mix, but instead to insert a blank track and do ONE comping/recording on that track, flatten it, take the lock off, bounce to clip, and then drag/copy that clip to my "real track", where "real" is defined as the track belonging to the mix.

 
Once you have your newly recorded and comped material bounced and moved into the "real track" (where I suppose you have the original/older comped material) do you then "comp in" sections of the new clip, blending it with the older comps, or do you keep all of the older and newer "comp sections" separate?
 

How about locking the position and data of all the clips in the track

 
I have tried locking the older comped Track Lanes when recording new Track Lanes into my track which contains previously comped sections. Locking the older Track Lanes is the only way I've found to keep from losing my original comp edits when recording new track lanes.

This isn't an answer to the question, but it's something I've started doing because of issues like the one you mention.
 
I use at least two projects for every song. One is a "takes" project, containing everything that was recorded for the project. All the MIDI (frozen but not deleted, with all the soft synths loaded), all the take lanes, everything.
 
When I get far enough that I know what takes I want to use (including comped stuff), I bounce to track and paste or import the selected tracks into a new "edit & mix" file. I do all my edits on that project, including mutes, envelopes, Melodyne fixes, timing fixes. This makes for a much cleaner and more streamlined working project, immune to things like hidden tracks making mysterious sounds, having to troll through a million snippets on a thousand tracks to know what you're looking at, etc. Also, if I make a mistake that can't be recovered (yes, it happens), I just go back to the "takes" project and grab the original.
 
If any more tracking is required, it goes on to the "takes" project.
 
When it's time to do the mixing and mastering, I mix on the "mix & edit" project and bounce all the tracks to one stereo mix track with lots of headroom. Then I mute everything else and apply mastering tools to the mix track, followed by a quick bounce to a "master" track.
 
It's more trouble, but it's bailed me out of the consequences of stupid mistakes more than once.
 
It just occurred to me... Wouldn't it be cool if you could have projects with multiple pages, like spreadsheets in an Excel workbook?

I like the idea of creating different projects for each song, like a working draft and a final version. Thanks for the suggestion!

I avoid takelanes, good idea but it's not ready in my view.
Consider using track templates and project templates to speed up your workflow.

vanceen
I use at least two projects for every song. One is a "takes" project, containing everything that was recorded for the project. All the MIDI (frozen but not deleted, with all the soft synths loaded), all the take lanes, everything.
 
When I get far enough that I know what takes I want to use (including comped stuff), I bounce to track and paste or import the selected tracks into a new "edit & mix" file. I do all my edits on that project, including mutes, envelopes, Melodyne fixes, timing fixes. This makes for a much cleaner and more streamlined working project, immune to things like hidden tracks making mysterious sounds, having to troll through a million snippets on a thousand tracks to know what you're looking at, etc. Also, if I make a mistake that can't be recovered (yes, it happens), I just go back to the "takes" project and grab the original.
 
If any more tracking is required, it goes on to the "takes" project.
 
When it's time to do the mixing and mastering, I mix on the "mix & edit" project and bounce all the tracks to one stereo mix track with lots of headroom. Then I mute everything else and apply mastering tools to the mix track, followed by a quick bounce to a "master" track.

 
I do something similar. I stick with one single project until the accumulation of tracks that I have finished working on starts to get in the way. Then I do a Save As to a auxiliary project, so that I can delete surplus tracks from the main project. I might do this several times and end up with separate auxiliary projects for lead vocal takes, backing vocal takes, guitar takes or whatever. If it becomes necessary to rework any of these things, I open the relevant auxiliary project and, when finished, export the result and import it into the main project. I sometimes do this with some individual softsynth parts too, as a way of reducing the number of items in the Synth Rack.

OP Albertb -- you asked "Once you have your newly recorded and comped material bounced and moved into the "real track" (where I suppose you have the original/older comped material) do you then "comp in" sections of the new clip, blending it with the older comps, or do you keep all of the older and newer "comp sections" separate?"
 
Let me first say that what these other folks are suggesting seems way too complicated.  I have been using Cakewalk since Cakewalk was founded.  What this post was originally about was "comping" and how to safely comp without issues.  Follows is an example of what I suggest:
 
Let's consider a vocal track on a 5 minute song.  The vocal is actually comprised of verses, which naturally breaks up the track into sections (verse1, verse2, verse3).  It is not practical to try and comp the whole track being 5 minutes long.  I create 3 new tracks, and comp each verse on its own track.  When all that is done, I flatten each, then drag those clips onto the vocal track (now consisting of 3 comps) that is part of the mix.  Then I archive the 3 comp tracks.