Every one gets kicked at once: [SEVERE] Reached end of stream for /IP

My Mincraft Server kicks regulary everyone and the console says:
2013-06-15 13:03:25 [SEVERE] Reached end of stream for /194.209.232.41
and this for every player.
This Problem exists since I set the server up maybe 13w17a or something, I kept updating (current 13w24b) but there was no change.
There are two sorvers running on this machine the other one is bukkit 1.5.2-R0.2 here is the same problem but it happens less often.
The wierd part is it does not happen simultaneous, I tested this, because I thought of a fire wall problem.
Another intresting fact is that the console brings the same if I click on refresh while in multiplayer menue, only the snapshot console does this, the bukkit console says nothing.