changing default text editor

[Archie Benton]

I'm trying to change the default text editor from gedit to
gvim. I go to the "preferred applications" menu and change it there
but it always defaults back to gedit. What's wrong? I can right click
and select gvim and open
the file but I'd like to automagically do it directly. I know there's
a config file somewhere I can thrash about in and force this to happen
but what's going on with the gui that prevents me from changing it
that way? Thanks.