could it be that a while back you told zonealarm to allow 2.6.5 through and later forgot to tell it to let 3.x through?

maybe that's why 2.6.5 works and 3.x doesnt.

check your zonealarm settings

2.6.5 is obsolete and i think newer versions don't connect to it any more, so you're probably connected to a fairly small network of vintage limewires, with a fairly small amount of total shared files. it would make sense to get 3.x to work.