From personal use U3 is really quite crappy, and you would be better off switching to something like portable apps(free and doesn't require the CD-emulating chip in the flash drive, so if you end up switching you just have to copy paste your files). The only interesting thing I've seen from a U3 drive was an autoplay virus based around the fact that U3 can autoplay without asking... removing U3 isn't fun either(at least it wasnt when I did it, may be easier now though...) This might not fix your problem though, but its worth a shot...