Portools, G3 and OS X...I need help!

[Vard]

Hey everyone...

I have posted a couple of times about getting a small recording room
setup using:

Mbox with Protools LE 6.1

on a:

B&W G3 500
1 Gig of Ram
20 Gig HD

Well, I finally got the Mbox this week and spend that last couple of
days getting things installed and everything hooked up. Pretty easy,
at least so far. Haven't done anything fancy or messed with the
software much beyond getting couple of tracks up and running.

But I have run into a problem I am hoping somenoe can help me with.

I am getting an error that "CPU usage is holding off USB audio -9136."
It gives a bunch of options, some of which I have tried and some of
which I don't yet understand. From Digidesigns website I see that
others have had this issue as well. Anyone here have it...and what do
I do to fix it?

I called up the CPU meter to monitor the usage and it is barely being
touched, so I don't understand the error. We aren't running anything
fancy so far as I know. Strait mics into the Mbox recording 2 tracks
with no effects...at least until after. The warning shows up what
seems to be totally randomly. Sometimes 2 seconds in, sometimes 2
minutes in.

My first thought was a CPU upgrade, but since I can't really afford it
right now, and since the CPU meter is showing plenty of room, that's
out. My other thought was to use OS 9 and Protools 5.x that also came
with the Mbox. But I have a feeling this might lead to other issues I
don't want any part of. Any thoughts on doing something like that?

Anyway, for what we could get done last night, it was pretty fun. I
appreciate any help anyone can shoot my way on this.

Thanks again,
Eddie