lots of white noise, pops, clicks, and dae error 9073

[tom devilution]

protools hd3
software version 7.3.1
mac os 10.4.10
3ghz 8 core
2 maxtor usb 2.0 500gb external drives

once i start digging in to a session i'm getting lots of noise and pops and clicks and a dae error 9073. of course i can't get it to give me the error right now so i can't state it exactly but it's more or less telling me it can't get the information from the drives fast enough. i've done a much higher track count with firewire 400 drives on a much older machine and have not have this problem. is there a setting i'm overlooking? help would be appreciated.
-tom

[DigiTechSupt]

2 maxtor usb 2.0 500gb external drives

i've done a much higher track count with firewire 400 drives on a much older machine and have not have this problem. is there a setting i'm overlooking? help would be appreciated.
-tom

Yes - USB drives are not supported or recommended for use with Pro Tools and are known to be problematic. If those drives have a FW400 connection, you should use that.

[tom devilution]

i've tried that and had similar problems as well. are there any settings i should be focusing on?