slk roof open or close problem

Anybody having a problem with their roof ? Mine sometimes makes me wait 5 minutes before I hear a click from a relay and then it opens or closes. The roof begins to open or close by opening the trunk, then nothing happens, you can keep your finger on the switch or not, that just runs the pump and the switch gets hot. After a while you'll hear the click, you try the switch again and it works fine finishing up the open or close whatever you were doing. Anybody have the same problem ?