The issue is dual view. If you are using dual view in XP and not having framerate problems then you have seriously overpowered hardware. There's a sticky about it at the top of this very forum.

Microsoft completey rewrote the multimonitor/adapter level of the OS for Vista... http://www.microsoft.com/whdc/device...imonVista.mspx


I'm sorta surprised that you were doing this without Vista Keyclone, as anyone who wants good framerates in XP will have to use horizontal span, and keyclone doesn't need anything new to support that.