We have just made a small change to our login system: if your IP address changes since your login then your session will be closed and you will have to login again.
This will reduce the chances some malicious software or web sites could use the tokens we give out when you login to impersonate your user here on Geekzone.
It may be an incovenience for some mobile users since those are more likely to have their IP address changed without notice. If you see a message stating your session terminated because of your IP address changed then you will know why.
This is the default behaviour. There's now an option on your profile that will control this and you can turn it off if needed.