There's a race condition somewhere in the event logger code, where if you get calls or sms in just the right window it can screw up the database. I've had it happen a couple times before I updated to CSSU. It stopped happening for me when I removed the desktop conversation widget , along with several other problems, like hildon-desktop running at 100% randomly. I sometimes miss having that widget, but since I've disabled it, I've had 0 db corruptions and no random cpu spins from the desktop app.

One thing I did notice before disabling the widget: When I killed hildon-desktop or rebooted the device, as soon as the desktop came up again I'd get a sms message. That's what lead me to suspect sms reception was part of the desktop issues, and/or to try disabling the conversations widget.