Tom -- I told you you didn't understand AoO, you magnificent bastard!
Mal is right on target. No AoO in the sqaure you're disengaging from, but AoOs in the new squares you enter.. from the Sage:
"How can I get away from someone without provoking an attack of opportunity?
"Once you factor in the effects of skills and spells, the game offers a plethora of ways to escape a foe unharmed. Even if you don't have a spell or skill to get you out of trouble, you can disengage from an opponent and not provoke an attack of opportunity just by moving.
"If all you do during your turn is move (not run) the space you start in (generally considered a 5-foot square) is not considered threatened and nobody gets attacks of opportunity against you. If you later move through another threatened area, however, you are subject to attacks of opportunity. (If your opponent has reach, you can forget about getting away without drawing an attack of opportunity.)
Even if you take advantage of this rule, you'll need to have a better movement rate than your opponent or move someplace where your opponent can't follow to get away clean."