PowerBook - Something wrong with my powerbook?

Hi, I'm just wondering if there's anything wrong with my Powerbook?

I've recently bought eyetv from the apple store, I returned the first one sent as it didnt' work and the replacement one doesn't work either.

I've also just bought a 3g datacard from vodafone, and that doesn't work either.

Powerbook can't see the data card (altough it did detect an old one I had - although that didn't work either) so I know the card slot is working. It also crashes my mac. The eyetv just can't see a signal at all, not even 1%.

Is there anything wrong with my mac - just seems a co-incidence that both things replacements won't work.

I've recently bought a USB hub from ebay - which is a bit tempremental, was wondering if that was the problem - but I've unplugged that and still the two items won't work.

Can someone please give me some advice as I really don't know what to do. I'm starting not to like my powerbook now as I can't use it away - not really much of a laptop!