Okay, I have just gotten a confirmation about the 9100. Failing to find an email address on the ATI site, I went to Sapphire, who makes the Radeon 9100 Atlantis cards. After only a couple of hours I received the following reply:
"This card is indeed a R8500 with an updated products ID. I cannot say wether the driver works or not in other O?S."
He may not know, but I'm guessing Forefront does...
Kay