okay i have a 24" intel iMac from 2 years ago and it has USB2 ports on the back right, well if i plug in a flash drive and take files from the drive to the computers they transfer at USB2 speeds. But when i go the other day and copy from the mac to the USB drive it's slow as hell. like USB1 or worse speeds. I can't figure out why. It's not like that on my PC at work which has similar specs to the imac. Anyway know why the USB up would be so slow?