Are you rooted? Safestrap installed?
Rooted, no safestrap since I haven't tried other roms.
---------- Post added at 08:43 PM ---------- Previous post was at 08:42 PM ----------
I have tried to fix it with my own ROM but the problem seems to stem from the phone changing to a lower CPU frequency. Usually happens to me about 30 seconds after I turn the screen off for just a moment.
I'll try it leaving the screen on and report back.