[CentOS] Disable notification in gnome

Hi all.

The Ghnome-notifications are annoying me.

it pops up, when firefox or transmission finished a download, when claws 
and sylpheed recieved a mail. balh. this is annoying. how can i disable 
the notofication per default for my user?
(the other users want to keep the notification)

-- 
Ibrahim "Arastirmacilar" Yurtseven
The web is what you make of it