Load your OBJ into C4D and make sure everything is grouped properly. You can't always tell in Poser... I had a problem with my Maradanian figure where one of the fingers was acting all weird. It turned out that ONE POLYGON had accidently gotten grouped in with the opposite part (that is, an lMid1 poly grouped with rMid1). I couldn't find it with the group tool, but it was plain as day in C4D. If you do find something like that, though, fix it with the Group tool, otherwise you'll have to drop way back to re-exporting from C4D and all that crap, and that's no fun at all... Also, make sure the red/green joint adjustment bars aren't turned around backwards. It's the silly, obvious things that really make you tear yout hair out;)