In their case they have the PS3 composite to the TV and "trying" HDMI for audio and it fails. Your setup is just another possible connection that I would take a bet would fail as well.
Is there any document you can share that this should work?
I'm facing trouble with the following connection :
Shaw HD cable box ---(composite cable)---Pioneer receiver
Pioneer receiver----(HDMI)----Optoma HD20 Projector
When I switch on....i get sound but no picture !! My AV receiver is connected with Bose 5.1 sorround sound sys.