I've been having this problem for a while but it's been on and off, however it's happened a lot this past couple of days. The only widget from your list that I have is the personal dataplan monitor so I'm going to try leaving that disabled and see if it fixes my problem.

Widgets I (usually) have installed:

Conversations Inbox
Email
Facebook
Personal Dataplan Monitor
Personal IP Address
Twitter

Thanks all, and fingers crossed