does a demoralized figure add +1 to a gang up attempt?

As far as I know, yes it does!

There are no restrictions from demoralized figures using gang-up. As long as they meet the requirements (front arc in base contact with target, no token, sword attack type), then they may use gang up.

well the confusion was with the origanal MK rules that stated
a figure w/ demoralize could not assist in a close-combat formation attempt..thanks for the clearing that up for us..

The difference between Gang-Up and the old Close-Combat Formation that made it illegal for Demoralized figures to assist in it is that a CC Formation requires all participants to make a close-combat action - something a demoralized figure is not allowed to do.

Gang Up, on the other hand, does not require anything other then what DB listed above.