[Sony Xperia S, Acro S, Ion] jtr165:
I've been running the only official lt28 JB firmware for over a month now on an LT28at with AT&T as the carrier. Overall pretty happy with it, haven't noticed any 'day 1' bugs accept for the video recording lag (which for whatever reason is phone playback only? on my pc, through vlc, all the video's look great.)

However, only July 22nd, Google released the updated maps app....and things have kind of gone south for literally anything gps related ever since...

The issue is tricky. After i installed the updated maps app, my phone froze on the map screen while searching for a gps signal. After about 5 seconds, the phone rebooted...but it wasn't a full reboot it seemed...it only took another 5 seconds or so before i was back at the lock screen. If i hadn't been physically looking at the phone, i never would've noticed it happened. Before this update; i had never encountered this problem.

After the kind of 'mini' reboot thing...no matter what, any gps related app (my tracks, gps status, Torque Pro, etc.) would do exactly the same thing. If i turned the gps off or never used a gps related app, the phone would function normal as ever...after manually rebooting the phone by either a full reset, or just turning the phone on and off...the gps would function normally again...I could get a lock, could use any of the apps, etc...

after a few hours, though...it would freeze up on gps stuff again, and get into the same boot loop issue with any time the gps sensor was used.

I've tried rolling back maps, but the problem remains...and i'm kind of stuck now...I'm positive this showed up with the newest maps update, as i had been using JB for a while before it and never had any gps problem of any kind...

what i've tried so far:

flashed an AT&T ICS firmware back...gps functioned properly for 2 days without a single problem. because this is an LT28at, pc companion cannot do a repair for this firmware. I get a 'we couldn't find any software for this device' or something of that nature. I've wiped everything through flashtool, and reflashed multiple times, without any form of back up data. I'm not rooted anymore, as i wasn't crazy about the rooting method for JB to begin with. figured i'd just wait for the time being.

tried 2 different .ftf files of the same JB firmware...both have the problem.

clearing cache of any gps related app i have doesn't seem to effect anything.

the only thing that seems consistent is that the problem only starts happening after the phone has been on for a few hours. If it try gps after a fresh boot, it works perfectly. If i try again a few hours later, most of the time it freezes and quickly resets, but keeps doing it non-stop until i shut the phone off.

is anyone having anything like this? Any help would be greatly appreciated...

EDIT: this can be marked as solved i guess...found info on other phones with 4.1.2 having similar problems...something to do with memory allocation and the adreno 220 gpu...rooting and running a memory tweaker/task killer (greenify or autokiller memory optimizer both worked) has been a good enough work around for the time being...hasn't happened once since i switched autokiller to 'aggressive' memory management...no gps problems, and not one redraw...phone is actually running better than new now haha...