It probably is a faulty frame, I either have to yank it out of the frame full force, and to put it back in i need to lift the frame above the wheel's axle then let gravity help me out to push the wheel into the dropouts. My 725 is a breeze to remove the rear wheel.

The leader also has some extra space when i put the wheel in before i tighten the nuts whereas the kilo is a snug fit.