Sonar X3 files suddenly get too large

Do you mean the entire project folder, or only the {myproject}.cwp file?

Melodyne edits are actually saved in the cwp file if left unrendered. It is best practice to use small region FX for Melodyne and render them rather than leave them "active."

Currently saving a cwp takes about 3-4 minutes. It was almost instantaneous this morning when file size was 3Mb. I haven't recorded anything today, just straightforward editing, chopping.
While saving the project, I see a TMP file in project folder, that grows from 0Mb to 632Mb (current size of cwp), that's when saving is done.  There is plenty of space on my harddrive. Harddrive's in good healthy state.
What's happening?

Recovered! Thanks a lot. "Save" buttin was grayed out in Save as Bundle dialog because there were still audiosnap and slipstretched audio in the project. Edit-Select-All Audiosnap/Slipstretched command came handy. 
Thanks a lot for your help. 
 
BUT this is HUGE bug. This is my 4th or 5th incident. And I lost a whole day of work today. Sonar should address this immediately. Even by looking at how audiosnap transient markers are displayed and rendered when scrolling, one can tell it is not a solid implementation.
 
Sonar is getting away from me, getting unnecessarily complex even when I don't want it. Moving from v6-8 to X series was like moving to completely new platform. At the next big release, I'll consider other DAWs as a destination for moving, if it is going to be a complete new experience.
 
Sonar, please learn something from Adobe, their workflow, menus, every major feature are still the same way after so many releases, they maintained operability while staying current.
 
 

Whenever I work with Audiosnap, Transient markers or Melodyne, I always bounce to clip when I've done.

NeckHumbucker
BUT this is HUGE bug. 

It's not a problem if you know the cause. If you want to get rid of transient markers and slip-edits after using AS to split at transients just uncheck the Enable box in the Audiosnap section of the Clip properties with all the clips still selected immediately after splitting, and then right-click the selection and Apply Trimming. This gets rid of all the AS markers and slip-edit boundary tracking.
 
Having hundred or thousands of clips referencing small segments of each audio file will still make the the file larger, but not as gargantuan as having slip-edited clips with AS enabled on every clip.
 
A feature that allows doing this automatically as an option for Split Beats to Clips would be good to have.

NeckHumbucker
Any serious software company would take a data corruption problem very seriously, but that doesn't seem to be the case with Sonar. Look-and-feel is more important apparently.

 
There have been hundreds of fixes and optimizations in the transition from X3 to SONAR 2015 and during the past year, which gives a clear indication of Cakewalk's priorities post-X3/post-acquisition. If you truly believe that AudioSnap corrupted your data, then send the project to Cakewalk for analysis. If you don't clean up editing functions after editing has occurred, the expected result is that eventually the data will become too large to handle. Similarly, every time you bounce a track, a new file is created and that swells your audio folder. However, you could not do deep undos or have an edit history without that data. 
 
If what you're saying is there's no way to strip AudioSnap data after doing AudioSnap operations, I have not found that to be the case but then again, I'm using Platinum so things might have been different in X3.
 

Whenever you select Audio Transients in edit filter, audio gets analyzed for AS automatically, and even after you turn off AS at clip level, and change edit filter back to Clip, that AS info stays in the file, and then gets corrupt.

 
I believe that changing Edit Filter back to clip does not delete the AudioSnap data by design. To remove AudioSnap, Acidization transient markers, Melodyne metadata, and the like, you need to bounce the clip to itself. If bouncing a clip to itself does not eliminate the metadata, that would indeed be a bug and Cakewalk should investigate it.
 

I have a similar problem ...i do some edits, and then later i delete several tracks making the song smaller, but the newly saved file is much larger than the original and sonar starts working very slowly and sometimes hangs for five or more minutes. How do you remove the edit history? because I think this would allow the file size to get smaller?