I've just reflashed with Ubuntu Live CD after a multitude of problems on Windows Xp - just do it! It works straight out of the box with Ubuntu and is very easy.
Windows 7 X64 doesn't really work. Windows XP is more reliable, you could use a virtual machine such as Sun Virtualbox to do it.
remove the battery run the flash command and when it says "waiting" put the battery again with the usb previously plugged it works for me