SPIT I recently upgraded my system from windows 98Se to XP.
My "old" system coped fine with my Canon Ixus V3. I had two USB ports on my pc as well but purchased one of those cheap splitters (takes one slot and gives you 4 back) from ebuyer which was less than £10 or so. The camera worked fine being cabled into either the splitter or directly into the back of the pc.
Best of luck.