[HD2 Android Q&A, Help & Troubleshooting and Genera] voyager529:
Ironically, Bravo (the one presently running Android) was warranty replaced less than a month ago due to an actual, legit unresponsive screen. The fact that the pattern is consistently "screen stops responding/SoD/CoD -> hot reboot -> phone resumes working perfectly", and has been on both phones, leads me to put that particular explanation towards the bottom of the pile. Rather selfishly, the supplemental reason to that is that T-Mo isn't going to honor a warranty replacement for an issue that only happens on an operating system that is an unofficial port, so if it is some bizarre hardware issue, it's gonna be mighty expensive to get the phone swapped.

I have a thought about that that I'll get to in a moment...

No. good catch =)

I always use the NAND methods, but data is a bit hard to store without an SD card. You have inspired me to do a MicroSD shuffle though. I'll give that a try.

That is, in fact, the answer lol. Originally, Alpha ran Android and Bravo ran WinMo. This problem started, so I switched them around: Bravo was configured to run Android, and Alpha became the WinMo phone. Alpha, which would SoD with Android, has not done so in the weeks since it became the WinMo running handset. Bravo, now sporting Googleware, exhibited the same issues.

To answer your last question regarding whether it was the ROM, I tried the ICS ROM with stock kernel, Dormanix's kernel, Typhoon CyanogenMod (the most reliable in my experience), and HyperDroid. All of these ROMs did the same thing after the first day or two, but hadn't done so in the past: I used both the latest release and older releases that I've used and am 100% certain have worked for me, on my hardware, without fail. As such, this is starting to ratchet back to being a PEBKAC/ID10T issue, but I was never able to pinpoint anything specifically that would earn me a dunce cap. This morning though, I had a breakthrough...

Yesterday, I decided to ditch MAGLDR and opt for CLK instead. I must admit that I do greatly prefer MagLDR, but I was determined to try as many things as possible to get to the bottom of this. I Task29'd, got CLK in along with CWM Recovery, Flashed the ROM again, and started restoring apps from the Google Play Store. No reboots at this point, but then again, most flashes have worked wonderfully the first day. As an aside, I'm torn: I do like the greatly decreased boot time and increased internal storage availability, but MagLDR was much simpler to work with for frequent flashing chores. Oh well.

The stock lock screen gives me a camera launching option by dragging the unlock icon to the left. Being left handed, on more than one occasion I've ended up getting myself to the camera by accident because the side of my palm triggered the multitouch. As such, I did a little experiment. Using ROM Toolbox, I 'froze' the camera app; I never use it intentionally anyway. After doing so, I was curious as to how the lock screen would react. Behold! I finally found a way to consistently trigger a restart! This got me thinking two things:

1.) As much as I like taking out things like the stock news/weather/twitter apps that I never, EVER use, maybe one of those were being randomly restarted (as Android apps tend to do), and instead of giving up on starting the app, my phone instead decided to divide by zero.

2.) The utility of Advanced Task Killer and its ilk have been hotly debated in Android forums. Personally, I find ATK to be extremely useful and love its functionality. As such, it's among the first things I install. Hence, I wonder if, for some bizarre reason, ATK is either killing the wrong task, or its presence is wreaking havoc.

Thus, I have foregone MagLDR, foregone ATK, and foregone pulling out stuff in ROMs I don't want. Also, I bought the GOTO lockscreen to help me get rid of the camera launching problem. So far, my system uptime is 6 hours, 14 minutes :D

Joey