Experienced my first sleep of death last night.
So this issue I think in some way (as was suggested somewhere back in the thread) seems to relate to fully or nearly full batteries.
I ran for four days without having a single SOD power off/reboot issue when I was just car docking the cappy but never having it full charged.
Normally I do not charge my phone but use and external charger and two batteries swapping back and forth daily.
The SOD issues seem to happen with some consistency once a fresh battery is installed and then will cease to happen once the charge falls off.
I don't believe this issue is specific to this ROM as it has happened with other ICS ROMs like DOCs v5.
In the current config (last time I installed Slim 2.9) I flashed back to stock with a full wipe of the phone, re-rooted, verified the IMEI had stayed in place and did not switch the kernel. In the prior install of Slim I tried both the stock kernel and Glitch b5 with no obvious change in the behavior.
With that said it is running pure Slim 2.9 at the moment.
With a fully charged battery installed and then not using the phone (such as last night) it happened twice. Once before I went to sleep I hit the power button to wake it up getting the ATT bootloader image and it booted back up. Then left it. When I woke up a bit ago, hit the button, ATT and a boot. Battery still at 100% so... This has been a semi-consistent pattern with fresh batteries installed.
Since the clean wipe of the phone I have not set any overclock or undervolt.
Any thoughts?