Nah.. tried latest version (2.2.1) Rabit - no go.
RaBit doesnt recognize the bios correctly. According to mvktech.com its going to 'take a while' before a version supporting R600 is released.
Another issue: both the PRO and the XT bios (512MB) gives vddc 2.20V. Datasheet says vddc = 1.80V ?