It is possible that your isp has noted your heavy (I assume ) use of bandwith and decided to curb, or "shape" your bandwith use. It might be a good idea to check with them what their policy is regarding bandwidth use and p2p programmes.
let us know how you get on ... or come back with some more details of your equipment routers etc.
I have indicated where to find things on the forum and limewire site below
