If you haven't done so already, I would simply unistall messenger completely. Then fo to the windows live page and simply download and resintall it. That usually works well.
For a month now, every time I sign into Windows Live Messenger, it just freezes up on me, plain and simple. The weird thing? No matter how many times I click on the window or the icon and use task manager, I'm not prompted at all that the program is not responding, at all! Does anyone know what the problem could be? If it helps, I'm on Vista Ultimate.