My DS also ends up in funny positions. He's only gotten stuck in the slats once though. I figure he must've figured out how to get himself out (or his arms and legs are getting too chubby to fit). We do without a bumper, but I'd imagine your LO could handle it by now.
My DD does the exact same thing. I swear she's doing laps in there LOL
DD used to get her arms and legs caught and she'd also bump her head on the crib when we took the bumper out for about a week. So we put it back in. At this point it is safe IMO, but of course you have to know if you are comfortable with it.
This was DS. One night he woke up SCREAMING (not normal). MH ran up and he had his leg stuck in the slat and couldn't get it out. He had a red mark on his leg for TWO weeks because of this. I know this is not the norm but I didn't want him to get hurt again. We got a regular bumper (we got one that was't very plush). I was very worried the first few nights we used it but he accually doesn't move around as much since we put it in! I think it's because of the pictures on the bumper and that he can't see out into his room, he's not trying to get things on the other side of the crib.
Re: Sleep Mover!
My DD does the exact same thing. I swear she's doing laps in there LOL
DD used to get her arms and legs caught and she'd also bump her head on the crib when we took the bumper out for about a week. So we put it back in. At this point it is safe IMO, but of course you have to know if you are comfortable with it.