Unable to customise applications menu

[Joona I Palaste <palaste cc helsinki fi>]

I am running Gnome 2.6 on a Fedora Core 3 system. I am unable to
customise the applications menu in the panel. Every customisation
option is grayed out and if I try to edit anything in Applications:///
in Nautilus, I get a message that the file is on a read-only disk.
This happens even if I'm running as root. As far as I know, my system
does not include any read-only disks. Where exactly is the information
about the applications stored? Is there some kind of configuration
setting that I need to change to make Gnome see the disk as editable?
Thanks!

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/--Joona Palaste-------------------------------------------------------\
\----------------------------------------------palaste cc helsinki fi--/