Noise Blast from MBox on G4

[smsjr]

I know that similar problems have surfaced on these boards, but I'll lay out my scenario. I have been using my MBox with a Mac Mini, sort of a portable system that has saved me from lugging around a tower. Things have worked out nicely with that setup.

But when i try to use the MBox running PTLE 6.9 on my G4 Dual 1ghz running OS 10.3.8, I get horrible noise blasts (white noise, crackles) at very high decible level. I've tried all of the mac maintainance I could think of, trashed Digi prefs, all the usual stuff. This problem was there when I tried to do this initially when i first got my MBox. I gave up and just used it on the Mini. I can't figure out what is causing this. I was able to mix the spot I was working on, but as soon as I went to bounce it, the problem showed up and now it is there, even when i just try playing my tracks. Very odd problem, and potentially dangerous too. The level of this noise was quite loud.

I'll be in touch with Digi support tomorrow, but if anyone has experienced this and has found a solution please let me know. By the way, this was a very clean installation. No Pro Tools on this volume before today. So, reinstalling probably isn't the cure.

Thanks,
Steve