session crashing!!!

[gusto106]

help!!!!!!!!!!!!!!!! everytime i start a session and play the audio this error message pops up-CPU usage is holding off USB audio. Remove some plug-ins, delete some tracks, or increase the "H/W Buffer Size" in the playback engine dialog. (-9136) the only thing is with that is, i only have 1 track with 20sec. of audio with no plug-ins! also, when i play my audio, everytime i move my mouse, the same error msg. pops up. i am running an mbox ver.6.7 on an apple dual 1.8ghz powerpc g5 with mac os x ver. 10.3.9 Please help. Thank You in advance.

[magicm]

Every time you move your mouse? Are you using a USB hub?
Have you tried different USB cables?

[gusto106]

i tried 3 different "mouse" and still the same problem. the only time i can use my protools is when i keep reinstalling it. it'll work for about 8hrs and then i'll have the same problems again...then i re-install again and it works fine. i've been doing this for the past 2days.