1. Have you ever looked at the loading of the GPU?
2. Have you tried running GPU-Z while the application is running 1920 x 1080 @ ~23.976
3. Have you really read my posts where I stated GPU loading is minimal, madVr barely even loads the GPU when non interleaved HD is viewed!
GPU load in GPU-Z is notoriously unreliable. It measures, roughly and somewhat in the dark, only a subset of the execution units on the video card. But, even assuming it is reliable in this case, GPU load has
absolutely no bearing on hitting a driver bug or instability. I've
certainly had unstable video cards crash (almost always due to a flaky driver, but a handful of times due to hardware) seemingly randomly with low-load conditions. This can be caused by a flaky driver (either buggy or just a messed up installation), a flaky power supply, motherboard incompatibilities (sometimes down to the BIOS versions), or just a plain flaky card. But, often in these cases by pushing on the card, you can
make it crash by "exercising" the different execution units on the card. Pushing on it hard.
I'm assuming that because you have a lower-end GPU there, that you don't do a lot of high-end gaming, and so may not have ever really pushed on that card with something like Metro 2033 cranked up. 3DMark is just a convenient way to test it and cross that possible item off the list.
If you're reluctant to try, then we might not ever find the solution for you, if it happens to be that. Of course, it might not have anything to do with the GPU at all. It could be some other system on Windows that is crashing and taking down the display output at the same time. Or, it could actually be MC locking the display, I suppose. But this doesn't make a bunch of sense if you've tried exiting out of MC completely and the display doesn't come back. It really
sounds like the video card driver is crashing or locking up. MC certainly might be causing it, but it could be some other factor (or some weird combination of your settings and hardware).
I use MC with a variety of 1080p monitors, and with multi-monitor setups (some way more complex than yours) all the time. For example,
this system runs a 1080p detached display on an external monitor 24/7. It does crash occasionally (I suspect memory leaks in ffdshow), but it usually lasts WEEKS of 24/7 running before crashing. My HTPC is a 60" Panasonic plasma, and yes, I run it at 24p all the time. I haven't played with MC's auto-refresh switching stuff yet though, so there could be something buggy in that if you're using that. I also have my basement system which has three displays: 1080p @ 60Hz, and 2x 1280x1024 @ 60Hz. Until I smashed my laptop, I ran it connected to HDTVs and Projectors in a very similar model to what you're doing all the time, with Theater View on the laptop and the display on the external screen (though the laptop did have an Nvidia GPU). I have a LOT of systems at my disposal, being in charge of the AV systems at a medium-sized corporate campus.
I can certainly drop the resolution on one of my basement monitors down to 1024x768 and test it, though I can't run that display at 24p (even my "nice" one down there is still fairly crappy). Theater View on one display with a detached display on another certainly works perfectly fine here. Are you using a detached display fullscreen on the TV, or are you sending Full Screen Display View to the other monitor (I haven't tried that in a long while, I always use detached displays)?
But, if you want to actually solve the problem, we're going to need to start testing different things. You can't just say "this is the way I want it to work, and it is broken, fix it" because they don't know what is causing the crash, so there is nowhere to start looking for the bug (if it even is in MC).
We need to start systematically trying different things, one at a time, and find the problem. Then, they'll fix it if it is on their end.
But we do NOT have a huge rash of AMD GPU owners with gray screen crashes here (including the developers themselves who have similar hardware), so there absolutely is
something different/strange/broken/wonky about your setup in some way that is causing it.