what about your own computer? Does this have the possibility to install an optical drive with IDE interface?
What could have interferred with the flashing?
It could be simply the enclosure - 100% compatibility is rare.
On the software side, there could be applications and drivers being the culprit:
[li]Virtual drive software,
[/li][li]Packet writing tools like InCD,
[/li][li]Storage controller drivers
[/li][li]Copy protection stuff (from games, videos etc.)
[/li][/ul]If you can identify one (or more) of these, then you can try to uninstall these and try flashing again.
You could also try to connect the unit to another computer (still using USB) and then flash again.