As the PPs noted, you can usually get into a line for a ride right up until the park closes. Some attractions may have different hours than the park, but those are usually listed in the time's guide (like Toontown closing before fireworks and not necessarily re-opening). For the rides that closed a few minutes early, was it 2 minutes? 5 minutes? 10 minutes? I haven't had this happen, so I was wondering if it could be something to do with which clock the CM is going by. I've noticed that the clocks in DLR are not necessarily all in sync.