Wasn't sure where to post this... but here is my issue, My MacBook Pro appears to have got its USB Bus "Stuck"

It THINKS I have an iPhone 3GS connected in DFU mode, however there is nothing connected.

I've tried rebooting, I've put my iPhone 4 in DFU mode and plugged / unplugged in every usb port

I don't know what else to try... anyone got any ideas??

Many thanks in advance