[Koha] Items checked in/out problems?

Yesterday I checked in 3 items, waiting for each item to appear on the screen as truly checked in. I then checked the patrons account to make sure all items were checked in. All appeared well. Today, I checked the same three items in again-two showed correct status: not-checked out. The third item's status: was NOT checked in. This has happened several times, sporadically, over several months. Has anyone experienced this problem? Coreen Maas Public Services RMC Health Prevention Information Center Library 7525 W. 10th Ave Lakewood, Co 80214 preventioncolorado.org coreenm@rmc.org Work 303-239-8633 Fax 303-239-8428