MacBook w/ Leopard: Protools 7.4.2 loads but the sound stops

[AcZ Finch]

I have:

MacBook
OSX Leopard
MBox 2
Pro Tools LE 7.4.2pr

What happens is that i ill create a few tracks, lets say three. i have a master fader, a click track, and one track i want to record on. I get the mic set up to record my guitar and so i press record. after i press record, i can see the bar moving across the screen telling me where i am in the song, but i hear no sound. I can hear my guitar through the microphone via the Mbox, so that tells me that theres not a problem with the mbox, and or any of the volume knobs on there. and up until this point, i could hear the click track when i was just pressing play and practicing before recording. sometimes, a lot of the time, the screen will freeze entirely and i wont be able to move the mouse or do anything, and ic an't hear anything. once or twice an error message from my mac has popped up saying something about the CPU pathways or overload or something like that. I do not remember the specifics. I talked to a tech guy and he told me to turn off the air port, and try it again. I turned it off, tried it again. still no sound and freezing screen. someone please help me!!!


Stephen