Saw your post in Slush's thread, have you tried uninstalling and reinstalling Guiminer - maybe something got corrupted.
I'm using Guiminer and connecting isn't a problem.
K.
I tried another version that I have installed, and it works! Thanks!
I had "downdated" GUIMiner to have Phoenix for mining on Bitcoinpool.com, but I had the later version left too, and that works!