What game are you playing where an item disappeared? I have read posts before of a few people saying that items had disappeared from their inventory in some game, but I have never had this happen.
bpurdum, I had the same issue as well with the corn, but there is actually an invisible left to right scroll button for your inventory. Try clicking at the very side of the inventory below to make it scroll left or right. I found the missing corn that way. Even though you don't see it, it does exist for some odd reason.