The worst tome so far was some friend pics.

I think it happens only when you don't get all the prizes and log out.

Not so sure about that. I always log in & out unless the game freezes & I get booted from the server.

I was looking at my room furniture today & have had 6 items of my furniture not there that I had won! :'(

Guess I need to replay the mini games again. I don't remember which games I got some of my furniture from. :(

When prizes get taken away, do the present icons re-appear on the high-score table?

When that's happened to me, the presents have shown up again. Which is good, because otherwise I'd have no idea which ones I was missing!