Originally Posted by 123Guy

Once you get it working again, clean the tracks several times a year. You can spray them with WD40, wipe them clean and lube with either white lithium grease or something similar.
Also, periodically, do the same thing with your door latches - clean with WD40 and lube with lithuim - do that and you doors will continue to "snick" closed forever - unless that little plastic piece at the bottom of the latch fails, then you will need to replace the latch.