Running an 08R2SP1 enterprise i7-920 server with a brand spanking new PNY Quadro 600 to test lab RemoteFX. Hyper-V manager recognizes a virtual 3D adapter that I can assign to a Win7SP1 enterprise guest. The fun starts when trying to RDC in. When the remotefx adapter is removed, no problem with RDC from a Win7SP1 enterprise i5-2400S workstation. When the remotefx adapter is enabled for the guest, RDC yields "The connection was denied because the user account is not authorized for remote login." Other than the Win7SP1 guest, there are no other VMs in this Hyper-V box, nor is there an active domain controller on this LAN.
Identical RDC sessions except for presence or absence of remotefx adapter.