WWE: SVR 07 Online Help =(

[Alpha]

Well, first off, I'm playing SVR 07 (WWE SmackDown! vs. RAW 2007) on the PS3 (don't know if that matters). It's connected to my router, which is connected to my computer. I forwarded the ports the instruction book said to, yet almost every single match I go into, it freezes at the start, and then it says the host left and there was a network error. I say almost because sometimes I can get into a match, but that rarely happens. When I host a session and people come, the same thing happens at the beginning, but it says I disconnected! Are there any other ports I should forward? What can I do? Any advice is greatly appreciated.