Picture download problem

I have a new Fuji E550 which uses Finepix Viewer. The problem is that when running the viewer or just Windows explorer the PC recognises the camera begins to find files but stops after 20 seconds with a high pitched "bleep" from the camera. 20 seconds later it will recognise the camera again (low double bleep from the computer) and then lose it again after another 20 seconds.
The same USB socket used for my old camera and for a new card reader works fine so what is the problem please? (I know that I can use the card reader but I would like to know the technical reason for the problem)
James

James-
Sounds like something you'll need to ask Fuji. It's not something that I've run into before. Most likely it's a computer device conflict. Check your manual to see if there are any camera settings you should change. You already said you know you can just use your card reader. This kind of problem is an example of the reason I only use card readers.

Thanks for your reply. I have contacted Fuji again today and they have no other reports of such a problem. They are baffled. They only suggest that I try on someone else's computer and , if it's a problem there, it must be the camera or the cable. If that is the case then this replacement suffers the same fault as the first camera!
I'm just in the process of looking for USB faults relevant to Windows XP to see if there is a known issue with the SiS chipset which I have.
James