Registrations after Meeting Date

I sent up a number of large group meetings on September 25 and 26.  On all of them I selected the option under registration to close registration after the meeting date.  The meeting on September 25 is over (scheduled from 8-9:30.  Just pulled the registration report and there are a significant number of registrations after the planned completion date.  Just saw one that came through on the September 26th.  Why did this happen and how do I fix the problem?