if the irresistible object bounces of the immovable one, it still stops, even if it's by a millisecond.
Untrue. I give you an example of the Apollo missions in space. In Apollo 13, they bounced off the moon not even by hitting it but by going around and thrusting into the gravity field. I also give you the theory used in the Lost in Space movie: theoretically, if an irrestible object is going at a high-enough speed, when it hits the immovable object (which is the sun), the gravitational magnetic field will cause the irresistible object to warp to another area in space. This is also a similar theory to what we use for creating power from black holes (we being the American/English alliance of scientists, not including myself mind you).
I also give you another example that even in space, something normally immovable is logically movable due to it's very own gravitational field. But even if that were not so, we have two magnets in our hands. The immovable magnet which one hand is holding on to does not move, however the irresistible magnet will find itself unresisting to the immovable magnet.
Finally, the paradox originally given has to do with an unstoppable force and an immovable object, not an irresistible object. I admit I don't entirely know how it goes in quantum physics, however I do know how to think outside of the box, or at least think above the Earth anyways. Also, remember, just because our language considers something immovable-doesn't mean it is immovable in the universe.
Edit: I will try to give the proper theory on the latest paradox by tomorrow (or today? lol) since I'm going to bed now.