The Dell 5100MP, Vista Ultimate and the 'Connect to a Network Projector' feature

I am able to ping my 5100MP projector from my Dimension 9200 (which is running Windows Vista Ultimate) and I can also communicate directly with the built in web page (on the 5100MP), but I am unable to get Vista to see it (as a 'network projector') when either trying to 'discover' it, or when I enter the IP manually - I get the following message; "Windows received information from the projector that it can't interpret..."

 

Any advice on this one... or am I under the mistaken belief that I can actually output video from Vista to this 'projector' over TCP/IP?

 

Mike