That's exactly what xyz`1 said. Its called a. Sleep of Death
I just got it too, for the first time. I hardly even changed anything from the version I've been running fine on my phone for weeks too... no idea what's causing it.
Wifi seems a bit screwed too, randomly.
I expected to screw it up sooner or later with the number of patches I was adding, expected it to happen sooner really - it was just experimental to test out some patches that could eventually be added to CyanogenMod.
I'll do another version based on Tom G's & add a few patches from my old kernel to it (undervolting, gpu write-combining, updated ondemand cpufreq governor, no fsync, etc). I started work on it this morning just after I compiled mine.
It's not ready yet, but you can watch my progress here:
https://github.com/John-Kenney/kernel_zte_blade/commits/2.6.35