The MBP I have in my signature is having problems with both its USB ports. I noticed a few days ago when I connected my USB flash drive that the transfer speeds were slow. So I tried switching to the other USB port and still found slow speeds, so I tried a different USB flash drive and still found very slow speeds, transferring a 1GB file to the flash drive was taking 3 minutes. Other things like connecting my iPod and syncing it took forever. When I check system profiler and USB, my flash drive and everything else shows that its connected as USB 2.0 and showing that max speeds should be 480 MB/s, so I am not sure what is wrong.