Ok, when i try to authenticate itunes i get a itunes store error occured -50 . at first i suspected a network problem but that is not the case as all my pc and real macs can use itunes fine and authenticate? i am using itunes 7.3

plz help

hacintosh specs:
MSI PM8M3-V Mother Board
Random 20GB HDD
EVGA e-GeForce FX 5500 (Fully Working)
Intel Celeron D Prescott 2.8 GHz (SSE3)