Frequent USB freezes. No system probs.

Hi guys, first post on this site, hope u can help.

This has been doing my nut for a few weeks now. I been getting what i think is some kinda usb quirk.. on desktop/in game [lesser extent], i get mouse/joystick (usb?) freeze that may last between 1-5 secs. these occur at varying times, sometimes i could go days without it, other times, like today, its happening every 5-10 mins or so.

If im on desktop, i can unfreeze the mouse by hitting 'esc', where as in game, i have no option but to ride it out.. if im playing say battlefield2, i could be in a chopper... without warning, my cyborg evo ceases to respond, the chopper lists and inevitably crashes unless life returns in time for me to make some manner of recovery manoever :P

My pc isnt that old (less than 6 months), ive built a few before, this one is otherwise very stable and gives me no issues. all drivers are latest etc..

Spec:
AMD64 3500
Asus A8N SLI delux
120bg/40gb ata's
2gb ram
XPsp2 fully up to date
bfg 7800gt
Audigy2 zs

in case there are any known issues, ill let u know my peripherals:

Nostromo Speedpad n52
Saitek Eclipse keyboard
Logitec g5 mouse
Saitek Cyborg Evo.

Any help, or ideas greatly received.