I can verify this problem... on 2.61, I can pull ShoutCast through aVirt's Spaghetti proxy server. upgraded to 2.63, and everything dies with a Connection to Host Lost failure. Downgrade back to 2.61, and everything works again. I refer to these as "close'n'play problems" (close it... it plays. Open it... it stops!)
It appears to be ignoring proxy settings, as it displays pretty much the same behavior as if I hadn't entered any proxy settings at all.