NeOteric gives an explanation (not too clear) about how to use a proxy for an isp that blocks. In their case they switch back mid way thru. I'm not sure about that but at least follow the first few steps:
A Fix for those whose ISP's block Limewire which is using proxies. And also for IP setting within LW see:
Force IP instructions & sample image & 2 posts after that. Using port no. (6346) in the ip box when using force ip. NeOteric used proxy v.5 & I guess the ip address for the proxy option box. Which version applies generally depends on the equipment I think.