gnome shortcut configuration

[Tendril <dont_u_spam_tendril@shotgunsandwich.net>]

I have gnome 1.4 running on debian 2.1.1

How do I configure the keyboard shortcuts:

In mozilla alt-left arrow should go back and alt-right arrow go foreward

But instead alt-right arrow hides the application (even fom the panel) 
and alt-left arrow restores it. How do I turn this off as I like my 
keyboard shortcuts for browsing ( I use a laptop)

Many thanks

Tendril