I don't think it is the Airport Express router because LimeWire was working fine last time I used it, and I haven't changed anything that I know of.

I did not have any trouble using LimeWire when I first set it up on this system, iMac G5 with Airport Express with Earthlink Time Warner broadband.

I think my problem could have something to do with Little Snitch. ?????

I don't have any other virus or spyware stuff on this machine, so I don't know what else it could be.