Make sure you have the latest version of WLM and any updates that go with it. If it still is buggy try un-installing and re-installing it. You will have to re-add all your contacts manually do this, unless you can find them and save them. For what ever reason, WLM does get corrupted from time to time. It's happened to me a few times and and a complete un-install and re-install was the only fix for me.