Can't Login action=invalidkey

Hi there I recently tried to login into my wordpress site and I got a message in the address bar saying action=invalidkey and i cant get it, so i tried resetting my password and it did the same. I then tried chaning my password using cpanel and i still got the error.

Any clever people know why this is happening? Im using 3.5.2 and i recently installed wp login security 2 would this have anything to do with the issue? I recently got an email from the plugin stating it had locked an ip address out but it was not my ip.

Any help would be very welcome as i can now no loger access my wordpress site.