What I have done so far:
1) LGNPST'd to Stock and tried Offical CM11 without restoring anything. (I also reformatted the whole internal sd card). Issue still present.
2) Tried several other ROMs (SlimKat, PSX, Carbom) all with a completely clean install. The issue is present on all.
3) Tried Stock ROMs (EG8, SlickV5) The issue goes away.
4) Formatted external sd, just in case. Still present.
5) Ran the phone on stock AOSP (not installing any apps/changing settings). Still present.
Well I'm at a loss of what to try next. I have google'd around and found little info on the mmc1_detect wakelock. Some suggest it is a bad internal sd card, however I have tested it and it seems to be in good condition.
Please shed some light on this issue. Thanks.