When I have imported audio tracks and want to adjust the tempo, I make the change to the temp bar, and one track usually works fine but all the others then go out of sync. Is it possible to have multiple tracks affected by tempo changes?
 
Thanks

Sounds like the one that works is a Groove Clip and the others aren't. If you have The Big Book of SONAR Tips, refer to "How to Change the Tempo of an Entire Project" on page 282. Short form is slip-edit all audio to the beginning of the project, bounce the clips to themselves, then use Process > Fit Time. If you don't have the book, check out the Fit Time documentation. It's not transparent, but if I can figure it out, so can you 

You can also slip edit clips to the beginning then bounce them to themselves, Then enable audio snap on all clips that you want to follow the tempo. Note: you will need to click the option CLIP FOLLOWS PROJECT -autostretch in the audio snap view of each clip (you can use quick group and change this setting on all clips at once). After enabling clip follows project, you can freely change the tempo or tempos (create ritards in audio not there) make your band follow the original artists tempo map. Once tempos are settled on, you can bounce to itself or let that happen during mixdown.

If the project tempo is already matching the audio, then you can enable 'Follow Proj Tempo' on all the clips at once in the Audiosnap section of the Clip inspector, and all tracks will stretch/compress to follow changes and their start times will stay in sync.
 
See this post: http://forum.cakewalk.com/FindPost/3532448
 
But if the project tempo isn't aligned to the audio to begin with, you'll need to address that first. I always recommend using Set Measure/Beat At Now (Shift+M) as the most effective way of doing this. I can point you to other posts about doing this.