Because you must be running Mok's, and ragwort did some testing with skill lvls:"MM6-v1.0 can have magic skill levels built up to max of 28 w/ max double rounded multiplier skill level of 63. Constraint MAY only apply to offensive spells (not that that helps.)
MM6-v1.1, v1.2 and Mok's can have magic skill levels built up to max of 63 w/ max double rounded multiplier skill level of
141."
He tested it with Meteor Shower, Dragon Breath, and Day of Protection... I guess Cures are separate 
I'm going to go ahead and install MM6 vanilla in a separate directory and do some testing on that!
Glad you got it cured though heh.