Have you tried reinstalling it like it was a brand new plugin? Its was completely rebuilt. It should not cause any problems updating it, but its really hard to say if you have other plugins installing. It could be anything from your theme to another plugin that conflicted with the updated. I have just ran multiple test on clean install, updating etc. and have no problems. If you would try installing it fresh and see if it causes you a problem please. Since twitter changed their protocols the plugin was rebuilt entirely. There is not one piece of the same code in the new as in the old, but i can guarantee you its still the simplest, most flexible, easy to use twitter plugin out there.