similar issue with solution here:

http://forums.sketchucation.com/viewtopic.php?f=61&t=29422

This example leaves the receiving cylinder on the platform as static, but you can disable static on that cylinder's group.

jeff

Modified a bit with a hidden wrapped collision volume approximating the cylinder (the one on the top). Show the collider by enabling the HiddenCollisionVolume layer. Now the cylinder itself is ignored and represents only the visual.

jeff

adds a hidden collision volume around one of the pipes (see HiddenCollisionVolume layer)