Ever had that? I really need to leave, but I have only one hour for my move left in that game, so if I leave, I'll lose. But the opponent does not play either... so I wait and wait... finally, when his clock says -9 minutes, I leave. When I come back, I lost on time - he came, made a move (sitting on -9 minutes!) and won on time. Frustrating.

Now I understand that the timeout demon cannot be run every second (or the CPU would do nothing else), but what about this:
Whenever someone goes to a game page to make his move (and the system knows that he is the user due to move), the remaining time for him is checked, and if it's <= 0, he loses right there.
That would mean that without him opening the game, he could watch the time go to -1, -2, -3 mins, same as now, but he has already lost, the system just did not execute it yet. That would be fairer, and I think easy to do, without producing extra load on the server.

- this is my third idea in so many days; so if I bore you let me know. I thought they are all worthy. -