Unable to open any files through VFS in nautilus 2.8

[Dave Ahlswede <mightyquinn charter net>]

I've just noticed that, since I upgraded to GNOME 2.8, I can't open
files on any VFS protocol except for file:/// from nautilus. If I invoke
the program from the command line with a VFS URL dragged over from
Nautilus, it works fine, but if I click the file in Nautilus itself, I
always get the error 

"Couldn't display "proto:///filename". Nautilus has no installed viewer
capable of displaying the file."

I suspect it has something to do with the new MIME system, and something
not getting transferred over quite properly. Any thoughts on what to do
to fix it?