interestingly, i was looking at this today, we've done a few PS3s with the Nyko Bluwave IR dongle using MX-900s. Works alright, FF is a bit off but otherwise fine. We found we were using the dongles and getting a stockpile of nyko remotes, decided to try against all odds with a standard PC IR dongle - no such luck.

I'm under the impression that the IR sent is unique to the remote and means nothing to the playstation, it's the reciever that decodes it and then sends the right thing down the USB...the IR is just to get the signal over the air.