We are at Moodle 2.2.4+ (Build: 20120823) and since upgrading to 2.2 we have run into an issue with unenabled end/close dates registering.
A couple of times we have found that manually enrolled users, they have a start date but the end date is not enabled, reach the end date and loose access to the course they are enrolled in.
I now have a couple of courses where students are accessing quizzes only to be immediately kicked back out. When I checked the quiz settings, the open and close dates AND the allow access from / until dates are not enabled but are identical.
In ALL instances changing the end/close/until year to something in the future resolves the issue whether or not the dates remain unenabled or not.
While I can fix these problems on an encounter basis, does anyone know of a permanent fix? I haven't managed to find any other references to this type of problem or a permanent solution.