diff -r eb0b520564bb -r 800d1bd9021a gameServer/JoinsMonitor.hs
--- a/gameServer/JoinsMonitor.hs	Fri Jan 17 16:31:36 2014 +0100
+++ b/gameServer/JoinsMonitor.hs	Fri Jan 17 16:29:11 2014 +0100
@@ -24,7 +24,7 @@
 
 
 cleanup :: JoinsMonitor -> UTCTime -> IO ()
-cleanup (JoinsMonitor ref) time = modifyIORef' ref f
+cleanup (JoinsMonitor ref) time = modifyIORef ref f
     where
         f = Map.mapMaybe (\v -> let v' = takeWhile (\t -> diffUTCTime time t < 60*60) v in if null v' then Nothing else Just v')