I have a bunch of loops and samples I have purchased and loaded into Sonar X2.  Been using them for a few months without issue.  Now many of the samples have become distorted.  I am referring to the original sample files, not the samples inserted into my recordings.  Guessing I can re-install them and things may fix themselves, but wondering why this would happen so I can prevent it in the future.  Anyone... Beuller... Beuller ?

Check your routing all the way from clips > tracks> busses > master
Make sure nothing is clipping at any point in the chain
Try disabling any Fx - these could be overloading at some point
Examine the waveforms, do they LOOK as though they're clipping?
Do they distort if you play them outside of Sonar?

squonk2
...Now many of the samples have become distorted.  I am referring to the original sample files, not the samples inserted into my recordings...

How are you listening to the "original sample files" ?  If it's through Sonar's media browser, uncheck "Preview at host tempo" (click little triangle beside "Media") and see what happens.
 
 

Bingo Paul !  turning off preview at host tempo cleared things up.  Kinda sucks tho as I like to hear how it blends with some other tracks, especially for drum samples.  Is there another way to preview samples/loops other than through Sonar's media browser ?

squonk2
Bingo Paul !  turning off preview at host tempo cleared things up.  Kinda sucks tho as I like to hear how it blends with some other tracks, especially for drum samples.

 
Glad you found the problem.  I think we've all been caught by that one, at least I have.
 

Is there another way to preview samples/loops other than through Sonar's media browser ?

 
File/Import/Audio has a play button once you select an audio file in a folder, but I'm sure it won't play to tempo though.