Problem fixed, post withdrawn.
Since I am unable to see how your model is set up, and based on what you have said, this seems like a bigger problem than just rotating your cannon, I cannot provide as much help as I otherwise could.
Try changing the rotational axis you are rotating the cannon on.
Could it be because you are using CaptainsSeat.C0 in one and BaseCenter.C0 in the other?
Maybe try rotating BaseCenter by 90 degrees and then running it again?