I'm curious to know whether anyone here has experienced a malfunction of a double rifle due to the "backing out" of an ejector (retainer?) screw.

During my recent trip to Africa, my double rifle suddenly refused to function (the problem was discovered on the range while sighting in). After the 4th round it wouldn't fully close nor could it be re-cocked. The rifle was put away for the duration of the hunt as the cause of the problem wasn't apparent.

While disappointing, it wasn't a huge problem as a back-up rifle was available.

The cause of the failure wasn't apparent at the time and the rifle was returned to the dealer after returning home. Shortly thereafter the problem was explained to me as being caused by the "ejector screw" having backing out a turn-and-a-half - something that apparently could only happen while the rifle was disassembled.

The recommended solution was to simply add loc-tite to the screw and to turn it back in. That was done and the rifle was returned to me.

"Before" and "after" pictures follow:

Before:

After:

Any comments and suggestions would be appreciated. How common is this sort of thing?