can you send a system profile (link in catalyst menu)

Have you installed the current driver:
http://downloads.activesilicon.com/l...-v02_00_00.dmg

Is you Mac in 32bit mode (not 64?... although it sounds like an older mac - so may not be an issue)

What other PCI cards do you have installed?
(remove the PE4 if not in use)
Have you tried with ONLY one camera connected - do you get the same result with only 1 camera?

need more info about your system to suggest further

S