I had FFXI working on my PC on my last install, but I reinstalled Windows XP earlier this month and it's not working now. Hamachi is something I have on this install that I didn't have on the last one. Otherwise, it's pretty much the same program set as I used before. I'm getting a POL error when I try to log in and check my version of POL Viewer, an error that says to check my network cables and that it can't reach the update server. I was browsing the internet at the same time with no trouble. Even disabling my Hamachi virtual network card doesn't let it connect, and it's registering the address and gateway my router is assigning. Any ideas? I'd rather have JP POL Viewer running on Windows just so I don't have to swap my JP PS2 and HDD into my TV area just to add more WebMoney points to my FFXI account.

EDIT: The new program causing the problem wasn't Hamachi. It was PeerBlock, since I used to use PeerGuardian. For some reason it blocks a lot more by default than PeerGuardian ever did.