Let me see if I understand you correctly.

You have a couch prop. You load a character, then load the couch. At this point you can translate the 'Body' actor of the character without the couch moving, right?

Next you apply a pose that came with the couch to the character. Now when you translate the 'Body' actor of the character the couch also moves?

Please confirm the the above is a correct statement of your problem.