There are both DM-Waisten and DM-WaistenFIX maps on server.
I am not sure what exactly was wrong with the default version, but while having fixed version avalible, I see no reason to keep *broken* version in map list.
The original version of Waisten crashes Linux servers when switching to the next map. There are few maps on the server that have the same problem (an issue with emitters) that also have fixed versions available, DM-TheOnion is one of them. OnionLE fixes the problem.
You'll notice that map vote always fails after playing certain maps and a random map will be selected, that's why. DC has a nice little script that picks a random level on a server crash.