Mac OSX 10.3.4/ProTools LE 6.4 crashing frequently

[craigh]

I just picked up a Mbox with ProTools LE 6.4 yesterday. I'm very new to the audio editing field but lets see if I can describe the problem. I'm just trying to pull some miniDisc recordings into my computer, do some basic editing, then dump the final tracks to disk as AIFF files. I bought the Mbox so that I'd get better quality A/D than using what's inside my G5 computer. Unfortunately, ProTools is crashing so often, it's basically unusable. Sometimes it crashes while recording, sometimes while editing, and almost always when using Bounce to Disk (I'm about 3 for 25 so far). I've tried locating the data files on different hard drives in case that was an issue but that didn't seem to make any difference. Here's my setup:

Mbox
PowerMac G5 dual 2 GHz with 1 GB RAM
Mac OSX 10.3.4
160 GB internal drive, 2 partitions - 1 empty (tried both)
30 GB external firewire drive (journaling off, IBM Travelstar, freshly erased, Oxford 911 chipset but only 4200 RPM)
ProTools LE 6.4

If things don't improve quickly, the whole package is going back to retailer (and if they really think they can enforce their "All Sales Final" policy, they've got another thing coming).

Another question, if this setup doesn't work out, any other equipment (M-Audio?, emagic?, MOTU?) or software (Logic?, other?) I should be considering?

Thanks