[SOLVED] Floating pets on separated beds

Hi! I'm having trouble with a separated mattress I made where pets seem to be floating on top when they jump on the bed :/

Here's a picture of the problem:


Here is also a copy of the package in case it's needed! www.simfileshare.net/download/4337454/ 

I've tried to reimport it and look at the rig / weights but it seems to be good (at least to me - but then again I'm new to making cc objects) so any advice is appreciated! Thank you!