[SOLVED] Firefox only logins

[pbrooks]

A bit of an odd bug with our current install of Contao, it only lets Firefox users login.
Something must be going wrong with the cookie somewhere, so far I've traced it down to User::authenticate()

$this->strHash is blank, so authenticate fails.

Any ideas?

[FloB]

Maybe Cookies are disabled in the other browsers?

[pbrooks]

Cookies are enabled, going to capture packets to get to the bottom of this.
It seems to be dependant on web server and not related to php.ini.
Our dev server is debian, the production server is Centos.

Edit:
Just checked the date on the production server, our provider hadn't setup ntp and hence causing the problems.