Adobe CS6 doesn't work in main user, but does in others

This is driving me crazy.

i have done all the obvious:

repaired permssions, disk etc.

trouble shooting internet search to no avail. (there are too many things here to mention)

tried to boot into safe mode, but safe mode freezes, and i have to re-install mavericks to get my computer running again.

sat for a day with applecare trouble shooting, then told to take it in for service.

got it back with a service report stating nothing wrong. but was told that the safe boot issue is "known" for the late 2013 27" iMac. (why applecare didn't tell me this, i will never know.)

still doesnt work.

AARRRGGG!