Hi Deko,
You are not the first to report this and it does appear to be solely the software for the .51 server that is at fault. All servers are unaffected in terms of being online, but administrating the .51 servers will not be possible until this is fixed, The main problem is basically the tcadmin software for the .51 machine keeps closing, I've got a support ticket in with TCAdmin and hopefully they'll have a solution for me, It may simply be a setting on the server that i have missed or perhaps an update to something on windows, I'll let you know when i have more info.