Why does my Xperia X10 spontaneously reboot? Several times a day I find out that my Sony Ericsson Xperia X10 is waiting for PIN entry, probably because of a soft reboot. It annoys me to no end, and I end up missing calls beacuse of this. Is there a tool or another way to help me find out what actually happened, when, and what caused that?
I read similar reports lately, related to Titanium Backup.. When it runs, it kills apps to back them up, causing the phone process to restart. If you aren't running something similar, I would recommend using USB debugging and the SDK to capture log data..  Known as "logcat" in the Android world. 

Oh -- Here's an easy way to capture and review log data on the device without the SDK -- 

Is it feasible to disable the SIM pin requirement to avoid the problem in the meantime? Could replace it with the Android pattern lock to retain some security.