I had the same problem with LW not blocking IP's that I put on the block list.
Some one told me about Peerguardian2 by Phoenix Labs.
I have it running on Vista 32 and it works beautifully. I can't even believe all the crap it keeps blocking. My download speeds increased, too.
If anyone needs help with it, message me. Otherwise it's here.
Don't forget to load the additional BlockLists
If you run Vista 32, make sure you
1. ALWAYS run it as Administrator and 2. Download the Vista Loader.

As it says on their site - it's FREE and you run it at your own risk.

I've been running it problem free and I won't even start LimeWire until Peerguardian2 is up and running!!

*kinda neat - PG2 also blocks the annoying ads when you're watching TV shows on IMDB.com but it doesn't block the show itself!!*