This is using GNOME, with X set up to be on by defaul when logging on...

   Whenever I first log on, if I immediately right-click on a file in the
file browser/manager window, and choose "Open With...", I get a dialog
box/window that allows me to choose a whole bunch of Applications to open
the file with.  Or, I can also enter in the program's name manually, or
use the "Browse" option.

   HOWEVER, if I expand a tree, AND/OR right-click on empty space in the
file manager, and THEN try to right-click on a file and choose "Open
with..." what happens is that I get the dialog box but NO APPLICATIONS ARE
LISTED.  Just a blank space!! The only option for me is to enter in the
name of the program manually or select one using the "Browse" option.

   This happens CONSISTENTLY.  If I do what I did in the previous
paragraph FIRST, then during this session of using GNOME, I will NEVER get
the Applications to show up again using "Open with..." on a file.  I have
to logoff and re-logon (usually as a different user) to have probably an
80% chance of having things return to "normal".  I say "normal" in quotes
because if I do what I did in the previous paragraph, then the bug shows
up again.