I won but my rating dropped!


Yeah, most likely you disconnected.
If your opponent seems to be taking a long time to move, try typing into the chat box, if your message shows up, s/he is still "there", just not moving. But, if you message does not show, you have been disconnected.
I was playing "Nothing As It Seems" today. He made a few moves and then just stopped. Of course he eventually ran out of time, but the computer never told me that I won. I waited about 10 minutes; then logged out. After logging in again I realized my rating dropped (possibly due to logging out). Was I scammed by Nothing As It Seems?