If the clips are as described here http://forum.cakewalk.com/FindPost/3205328, they already exist as waves and do not need to be exported unless there are effects being applied, a change in the sample rate or bit depth. They already exist in the Per-Project audio folder as wave files. Assuming per-project audio folders are in use. There is not even a need to open the project in SONAR.

pjkemp
I heartily second the notion that this a unexpected behavior. can anyone from cakewalk comment on why this is so? for what I am trying to do, this would seem to be a bug....
 
 I just created another post with much the same situation... thanks for the re-direct.
 

IMO this is  the way it should be. AFAIK the most common reason for exporting tracks separately is to use them in other projects, maybe non-SONAR ones. In such cases  the safest mode is exporting the full project length (regarding the timing in the target project). That sounds fool proof to me. And if you don't want fool proof as default, you can customize the settings to your liking. 
 
Then again, I've never had the need to export tracks separately, so it's easy for me to babble :o)
EDIT: I just read the post about song-per-track-situation and possible batch-export with varying track lengths.
In such a case it sure would be a useful feature.
 

Definitely not a bug. If you want to back up a song in a universal format that will work with any DAW, exporting each track as a WAV file that starts at the beginning of the song and ends at the end is the safest, most compatible option. I believe Sony Acid was the first program to do this, and it was greeted with much joy from Acid users because all the loops could be "flattened" into tracks you could bring into traditional DAWs for mixing etc.
 
As has been pointed out there are many ways to do exports. Don't forget that you can also export individual clips as time-stamped Broadcast WAV files. Then when brought into a project they will be placed on the timeline at the same place they were when they were exported.
 
The audio folder scook mentions is another way to have all your songs together in one place as clips.