Signs get frozen, and useless

[starg09]

Once in a while, a sign will get "frozen", and won't work at all until it is broken and replaced.

As you can see in the attached image, there are 3 green signs, and 2 red ones. No arena is being played at the moment, but you can see 2 have suffered this bug, and show old data (On eeven says 5/9, when there's only 2 people online and outside the arena)

http://i.imgur.com/zs9xwTk.png