Sometimes the servers are down, and we don't catch it right away. I'll have a look at them now.

Your stats haven't been removed from the leader board by anyone at LDW. There are 2 possibilities: 1) Other people have achieved higher stats than yours, and your stats are no longer high enough to appear on the list, or 2) You have been affected by a _bug_ in the stats server code that causes some people's stats to remain unchanged after a refresh, which we haven't been able to locate and fix.