I posted about this a while ago, and thought I had solved the problem, but it's back and worse than ever! I have a Macbook Pro 2.66 ghz Core 2 Duo. After upgrading to Lion, its constantly getting hung up, having to quit Safari and Mail. Sometimes I couldn;'t even do that, I'd have to force reboot the mac. Some on that previous thread suggested running disk utility-repair disk permissions. I did that, and it seemed to work. But now the problem is back. I've been trying to run Permissions verify before Repair permissions, and it's been running for several hours now. That can't be right can it? I remember this was the case previously, and I wound up just running Repair Permissions that time. Whew. Help?!