I was having trouble with the 2.9.* releases freezing my internet connections when it switched to and from Ultrapeer mode. Yesterday's 2.9.7 Pro release seems to have fixed the problem, or you could try checking "disable Ultrapeer" in the prefs.

2.9.7 isn't yet listed on the free page, but does show here: http://www9.limewire.com:82/download/2.9.7/