Possible bug in Gallery?

I tried creating a new theme in Gallery, following the instructions in
the documentation, and got very odd results that do not seem to match
what the documentation suggests. I started by clicking the New Theme
button, giving the Theme a name, and then going to the Files tab. When
I click the Find Files button nothing seems to show up. And if I click
the Add button files show up, but clicking Open does not seem to do
anything. But if I open the new theme in the gallery I see that my
images were indeed added. I think this may be a bug. Or am I missing
something?

Thanks,