Device freezing after saving activity

Hi ! Last saturday I did a long running activity (more than 3 hours) and again my device reseted automatically after saving the activity (and whener I tried to repeat the saving, It restarted again and again) and only after a hard reset I was able to save it properly.

It started to happen after the 3.00 update, anyone experienced a similar behavior and have a fix ? I have a 245M device.