After about 2 weeks, the smoke detector was on the floor - he just released from the ceiling. After that, he was also over. Whether it was an installation error on our part now (but - can you REALLY wrong glue ??), the ceiling texture (smooth and flat, neither greasy nor wet - "Stop") has favored the detachment or actually on the smoke detector itself is (Monday product? ), I can not judge.
The other still hold, toi toi.