i think you need to turn it completely off (remove and re-add batery), then hold down the U key when you plug in the cable, let it loop if it does when rebooting stops the flashing above should then see the phone and work. if you can, use windows xp, i found some additional problems with the drivers in windows 7 64bit relating to drivers not installing properly because of the rebooting, in reality you should see the phone as mass storage when turned off, if that is the case then you should then be able to flash it. good luck!