So here's a first...I cleaned the filter and vacuumed the pool, no problems. It was pretty dirty so I was going to clean the filter again when I was done, and had a little problem...the lock ring on the filter came unscrewed from the lid itself and came off! I can't get it to lock back onto the lid so now the lid is stuck on and I can't get to the filter. Any suggestions??? Is that supposed to happen or do I need a new filter housing???