I would like to post my 2 cents here too, cause this is bug or whatever it is so annoying that I want to smash my Xperia against the wall.
It started shortly after I upgraded my Xperia T to 4.3 (.295). First I thought it is caused by wrong USIM placement, but even if I pull it out and follow the click to be sure it is placed properly, reboots appear from time to time. I was trying to track the source of this with "standard" steps like factory reset, installing apps and do settings without using Backup&Restore app, testing another USIM however without success, using phone with/without microSD card. I even upgraded to latest bugfixing .199 today but those damn reboots persists.
Maybe these observations will help to solve this issue:
- reboots appear usually after using apps using internet connection (mostly local news, gmail, Chrome etc) and, whats interesting, when screen is off
- mostly when on HSPA, not wi-fi
- when I play music, using PowerAmp, not tested on other mainly because I have no other installed
- sometimes after the call
- once or twice it happened when unlocking the phone
- reboots stops only if battery is totally drained or if I notice smell of the the burning flesh of my thigh and I put my screen on/or reinsert USIM.
I will observe more, but Im loosing patience
There were no reboots when on stock 4.1.2 with locked bootloader with root. I also had to turn off SIM card lock, because I need to be reachable. I like this phone, 4.3 is nicely done but this is driving me mad. I consider to downgrade and visit my local vendor, but beforehand I decided to ask community.
Sorry if this is discussed somewhere else here, I just spotted this post and added my POW. Thanks for your help