It looks as though p2p sharing is being blocked thru the server. That's the impression I get anyway. Yes http proxy is an alternative worth trying. I can give you the links but I personally can't advise. All I can say is you may need to try a great many ip no.'s before you find one that works ... and if it works at all.

A Fix for those whose ISP's block Limewire pages 1 - 3 which have links to alternative instructions. (there's various types of proxies mentioned in this thread with off-shoot links to alternative instructions, etc.)