It's not that it doesn't work with the PS3. It's that it doesn't work with PS2 games on the PS3. I have to do more testing, but I'm positive I can get it to work.
I believe if I start the game using the Sixaxis, and then switch over to the DFP while in Sim Mode, I will be able to get it working. However, it is fully backwards compatible, as GT: HD has been using the DFP on PS3's since TGS last year.