dan le
Hi:
Bundle files is a wonderful way to get rid of all unwanted waves files that you no longer use.
By saving the song into a new folder still does not get rid of the wave files that you don't need.
Sometimes one of my song will go up to almost 2 gig, after playing and replaying different lines or instruments.
 

The "Save as" function with the "Copy all audio with project" only copies the audio referenced in the cwp being saved. It does not copy unused audio. The result of the "Save as" is functionally the same as creating a bun and the opening the bun in a new location. There is nothing gained by saving as a bun except one large file that is more prone to failure than the original project.

Hi:
I just did again as Scook said, just to be sure, and in the Audio folder, the file size is the same, in this case, 800 MGB but the bundle file is only 550 MGB, when I saved it as bundle and reopen under normal in a different folder.
So there is still a diiference in the way the bundle file saves a project and a normal file saves a project.
dan
 

Bundle files are compressed. That may explain the discrepancy.   

Always save your Cakewalk Project Folder to an External Drive.
 
Once you have it saved there, when periodically re-saving it again to the external drive, you can rename the folder by adding the current date.  Or, just periodacally replace it there, Then you can delete the exsisting duplicated content from the C drive Cakewalk Project Folder. Now you have a clean Cakewalk Project Folder on your C drive, and everything saved on the external drive, in dated Cakewalk Project Folders. This will keep you preject audio folders in tact as well.
 
You then can work from the external drive, by dragging any project folder you desire to work with to the C Drive Cakewalk Project Folder. Or, you can open the Cakewalk Project from the external drive by selecting open with "Sonar". Once you save the exsisting Cakewalk Project Folder to an external drive, you can now try the restore factor you mentioned to get back lost data. If you do get it back, also save it again to the external drive.
 
Best not to try and rename or move exact projects with audio folders in tact, this can cause the corruption you guys speak of. However, you can rename and organize the folders, just don't rename and move the cwp. files. Example, if you have A Cakewalk Project named Rock Guitar, and inside it is the "audio folder" and Rock 1, Rock 2, Rock 3 etc...You can safely rename the Rock Guitar folder name, but you do not want to rename Rock 1, 2, and 3 etc...You can delete Rock 1 and 2, and Rock 3 will still be in tact. So you can organize them here, just stay away from messing with names where you have audio folders. But you can move and rename the folder it is in.
 
Saving and working like this from an external drive will not hurt or change anything with the cwp files, as long as all the plug in info is still available on your hard drive.
 
So save path: My Computer/C Drive/Cakewalk Projects, to the external, then try your restore. if you get back the data, also save it to the external. Then you can clean up the C drive CW Project folder, and work from the external, and save periodically to the external. That is how I do it!...Free