Make sure u have media server share thing turned off on your ps3 options. I beleive its the last option under network options. It is known to cause multiple problems and I believe this is one of them.
My PSN Name is: EvilChronos add me if u want :)
END OF GENERATION PREDICTIONS "9-21-08"
PS3=130M 360=90M Wii=120M DS=130M PSP=70M
Other Prediction: The PS3 will overtake the 360 XMAS of 09 "9-21-08"