I had one of the 4 screws that hold the bottom of the mast base down come out this weekend.
I mention it only because I never thought to check it prior to this and I just happened to notice the screw fall out of the mast cup when I flipped the yak over this weekend.
It may be something you want to keep an eye on and check periodically. I don't know what the consequences of having them all come out is and I wouldn't really want to find out!
(Now I have to go buy and extremely long screwdriver to get that bugger back in.....