If you freeze, refreshing the screen sometimes helps. Another option is to close the Live window/tab but don't log off. Then get back in. Not helpful in really fast time controls though.
You might also take a look at the following. It is about disconnects but might have some stuff that can potentially help. Also, disable Flash for the site, if your browser supports that.
What are we supposed to do when a game freezes? There is absolutely no response and evently you have to leave. When you do you are given a loss even if you are ahead in the game. This has happened quite a bit lately. Is it my computer?