we have/had the same problem with our amature company.
Some people (and it is consistently the same people) seem to think they are allowed to arrive at any time they like and gain entry. It is extremely unsettling for the audience and the cast.
We now have a door bitch, and print on tickets and flyers "no late entry"
We also identify a time within the first 10 minutes when it is possible to "sneak" the inevitable late comers in however the problem is much less since we have begun to stand up to these self important upstarts.
I recently inspected a theatre that had two entry points one of which was at the rear of the auditorium. This entry point is used for late enteries.
