1.5ct Princess Cut Diamond Loose?

I got engaged to my girlfriend 3 weeks ago and this is the second time now the stone is loose. The stone doesnt move but if you shake the rinf just a little you can hear a ticking sound. We were told the first time that this could happen with larger princess cuts. The first time the head was 14K gold but after the jeweler damaged the stone tightening it, he had to replace the stone. He replaced the stone with a platinum head this time. Now after only 3 days the stone is ticking again. Is this normal or is the jeweler doing a bad job???