Only problem I've had with mine was...
This is a decocking safety test - Clear the chamber, close the slide with hammer cocked, then place a pencil with eraser end first in the barrel, holding the CZ52 muzzle up. When you use the decocking position of the safety lever, hopefully the pencil will not move and stay put. Mine sends the pencil out of the barrel, so I will not trust the decocker with a live round in the chamber, no way! There was a warranty retrofit when the first batches of CZ52's came out, but mine never got the new parts. If I can find them, I'll have them installed, or put them in myself.
There's supposed to be a small "Z" stamped into the side of the trigger guard, signifying that new decocker parts have been installed. When looking to buy one of these pocket rocket pistols, take a look.