I've done a bit of reading on the link attached. It has said that a maximum of two digital tuners are supported.

Does this mean I could not have 1x HVR 2200 & 1x HVR 3000 Hybrid? As the 2200 is effectively two tuners? The idea was to record 2 channels at once, while watching another

http://windows.microsoft.com/en-NZ/windows-vista/What-should-I-know-before-adding-TV-tuners-to-use-with-Windows-Media-Center

Cheers!