AMD PowerNow slows down USB 2.0 transfers
 

After looking around to find out why my USB2 connection was so cripplingly bad, I stumbled on a post on ebuyer's website, written by a chap called Denver Maxwell. Basically, this chap had discovered that if he left his screen saver running or dragged windows around on the screen, he got faster transfers and syncronisation speed, and he has realised that PowerNow is to blame.

http://www.theinquirer.net/?article=16554