Have had this happen, very rare. Will also change meds to inactive (more frequent than just disappearing), the inactive problem appears after a med has been sent for refill. Did you check the inactive meds?
I have noticed that New Crop screen is not holding/transferring the UOM. There is also still a problem with the meds being not codified and italics. The italics problem was very bad in 11.1.1 and seemed better in 11.1.4 but i have been noticing more and more of these. There was another thread about the codify problem.