I have had 5 games going at the same time since I started and only recently encountered that problem. My computer froze the game and I had to shut it down with the task manager. When I got back in, one of my games wouldn't let me pick up any items, even when I had sat there and watched it appear. It was really strange. I checked my other games and they were fine, so I went back to the first one and the problem seemed to be gone. Maybe it had something to do with my computer, not the game.

Fawn