I have a few different card readers on my computer. In Gnome, when I put a memory card into its reader, an icon will appear on the desktop.... and then the computer wll try to 'open' the card, but says it has no associated application. Ideally, I'd like to have a normal Nautilus (Or whatever it is that gnome uses for file browsing) window that displays the contents of the media. How do I do this?
Thanks!
edit: In the dialog for File Management Preferences, on the Media tab, the Photos item says "no applications found" and is ghosted. This is what I need to fix. How?

