I found out the real problem, when $gmt isn't showing..
It's because both the GMT and the Info Center plugin are using the same Execution Order in the same hook.
And with some forums, vbulletin loads the Info Center first..
So when it reads the Info Center it sees an unknown variabable $gmt, and skips it.
So, the real solution is to change the Execution Order in the GMT plugin from 5 to 4.
Or change the Info Center to 6.
W/e number u use, the GMT plugin must be lower than the one from the Info Center