Hiya, I'm having the same problem and trying to resist the temptation of making a new topic about the same thing (hopefully someone's reading this!)

Yeah I used to be fine, and recently (perhaps since I installed .NET Framework 2?) all downloads are averaging 1 or 2kbps if anything (even popular files)

I'm 90% sure it's going to be something like M$ limiting port connections or whatever similar issue I had to download a patch for or something a year or so ago.. (RAHhhh)

ANSWERS:
-XP home
-i try to keep this machine clean, firewalls are minimal, I use a Netgear router, and Avast! which is lovely and has never caused me firewall problems (i'm at home)
-2gb ram
-infinite HD
-2mb broadband with Eclipse (who are £30p/m and therefore usually very good to me about ports/unlimited etc)
-latest ish limewire pro
-port 6346 open
-unshared conenction
-no 'brick wall' firewall icon in LW