LE static/crashes during playback?

[earshatter]

Using a Macbook Pro, Leopard 10.6.3, mbox2, dv toolkit2, one ext sfx hard drive, one ext work drive. H/W buffer-1024, cpu usage-80%, DAE playback buffer-lvl 1. Using 36 tracks, but only have 31 active, and the session is far from full. Have QT vid active. Also, playing back in headphones, not through amp.

Problems:
1) when playing back, at random times, there will be static on top of the audio. I can still hear my tracks, but the bleed of the static goes in and out. Tried to adjust the buffers, seemed to work for a while, then just comes back.

2) I have my drives daisy chained as follows (since there is only one friggin 800 port!?), from computer-1TB drive sfx drive-to work drive. I had to change this way because PT crashed every 5 edits with reverse configuration. Using USB800 ports, as I don't have sata connection nor 400 connection. I am also crashing when using the file finder within PT to find sfx. Had to give up my tower, so can't use soundminer anymore.

Any ideas as to how I can streamline the system so at least I am not crashing? I'm not overloading the system...yet. My session will become larger as the movie goes along, however, right now I'm just starting this movie.

This is driving me crazy (excuse the pun!).

Any help is appreciated.