my EA81 had the same problem on the same door. like everybody's suggesting here, i poked around with coat hangars, banged the door with my fist, drank beer at it, everything. the interior handle definitely had some resistance to it, as if it were locked.
finally took the door panel off and found that the child's safety lock mechanism had slipped out of it's proper position. it was basically locking the car with no way to unlock it.