Question for co-sleepers

[mrscakes]

What do you do with a baby that seems more comfy in his own space but won't sleep there?? Z's 11 mos and we've been co-sleeping his whole life (starting in a sidecar co-sleeper and eventually in our bed). Our usual routine is he goes in his crib at about 8 (his bedtime) and when he wakes up around midnight I bring him to bed. We've gone through rough periods with sleeping before, but I'm not getting any decent sleep with him in our bed anymore. He tosses and turns, thrashes and crawls around, and tries to nurse on and off all night - but while still thrashing around which is NOT pleasant for me.

I'm not set on giving up co-sleeping, and I'd be sad to give up waking up to Z's sloppy kisses every morning... but it's getting ridiculous. He sleeps so peacefully in his crib, but I just can't get him to stay there. CIO is not an option for us, but I really don't know what to do. Anyone been here?