I've got two computers, with the mouse, keyboard and monitor connected through a Cybex Switchview switch. When I connect the viewsonic vg920 directly to the linux box, I can set the resolution using the System menu. However when I connect the linux box to the monitor through the switch, linux somehow cannot detect what the monitor is and resets the resolution to a much lower setting.
How can I make the monitor settings in Fedora 12 permanent, so that when I connect to the monitor through the switch I keep the higher resolution?

Some KVM switches have a maximum video bandwidth which they will handle. Are you sure your switch is rated to handle the higher resolution?

Thanks kakaka, we (my linux helper and I) created an xorg.conf file (apparently the recent fedora versions don't use this, they detect the monitor on each startup) and made the settings permanent.
And yes, the switch is handling the higher resolution just fine.