Description of Problem:
If you add a program to the "Open With" menu for
jpegs (I added gimp), it will no longer generate
thumbnails, even if I keep Eye of Gnome on the
list and set it as the default. (This is all with 2.6)

Steps to reproduce the problem:
I want to add a program to the "Open With" menu
for jpegs. Specifically, I want to add the Gimp.
So I click on a JPG, Open With... Other
Application... Then I click "Go There" to get to
the File Types and Programs box. Now this next box
is where I might be doing something wrong, because
it's not clear. I don't know what "Viewer
Component" is. Anyway, I typed /usr/bin/gimp into
the "Program to Run" box and hit Ok a bunch of
times to get out. Now, Nautilus will no longer
generate thumbnails. I even tried going back into
"File Types and Programs" and making sure I
selected "Eye of Gnome" as the default.

I'm not familiar with the gnome metadata, so the
only way I knew to fix this was to kill .gnome,
.gnome2, etc. (basically, .gnome*) from my home
directory.