FM12- Network issues

Hi I have been trying to play some network games with some friends on fm12 and like during the day at around 7pm it works great, I connect to my friends server fine, then he goes for 30 minutes to do something, and when he comes back it doesn't work...we try entering all sorts of different IP addresses like Hamachi Ip, IP Address but nothing works whatsoever, and the bit where it shows the recent servers, when i click join game, where it has the game of my friends it doesn't work, it just shows an 'unable to connect' error message, it's like every time he comes back at about midnight , well its 5 hours behind in his time but still it doesn't work... we use hamachi networks, we have all our settings the same in network game settings, then at this specific time it just wont work, if anyone could provide some help I would be most greatful, thanks