how does the ingame 2 factor auth work?

ingame 2 factor authentication had been enabled for me ever since it became an option, but never once actually did it ask me for a code
today it suddenly asked me for the code when i tried to log in but every single time i get an error msg that the info i entered is not valid even though it is
i tried to disable and re-enable it on the website, still can not login

how could i deal with this problem?
pls dont tell me to turn it off and play like that because that would make this function kind of redundant, i want to play with it enabled for security reasons

http://forum.warmane.com/showthread....46#post2783246

i forgot to mention that im not talking about email 2 step auth since that o recent feature
i had been using the google 2 step auth so far

I believe it does it through IP? so if its a different IP address it will ask for a code.

I know that but it doesnt accept the code ingame
I can not enter to the game at all because it says the code is invalid