Shawn–
I’ve had your same symptoms from Day One, but it’s only been with WAV files. It could be almost anything, too– it’d play part of the track, then cut out, then be OdB static, then play a portion from a completely different project in a completely different part of my file system.
The only way around it has been to change any WAV files I get to AIFF files, which has worked every time.
I don’t know if that’ll do it for you, but, if it does…
–Kelly