I rooted and installed the stock ICS leak firmware. After seeing some stability problems I wanted to go back to stock and unroot. I used Entropy512's "Kernel + cache + rooted UCKK6 system package" to return to stock then removed the root files (su, Superuser.apk, etc.)
However, now I will randomly lose my connection to the AT&T network. I have plenty of signal (4-5 bars usually - good coverage, I'm in the Boston area) but the "H" or "H+" will disappear and my phone acts as if it isn't connected. Checking Settings -> About phone -> Status shows "Mobile network state" as "Disconnected".
Usually if I enter airplane mode, then turn off airplane mode, it gets back on the network, but only temporarily.
Here is all the relevant information I could find:
Model number: SAMSUNG SGH-I777
Android version: 2.3.6
Baseband version: I777UCLC2
Kernel version: 220.127.116.11
Build number: GINGERBREAD.UCKK6
Signal strength (currently): -79 dBm 17 asu
Mobile network type: HSDPA
Service state: In service
Mobile network state: Disconnected
Thank you so much for any insight you can offer. Apologies in advance if my post is too noobish.