Gtk-WARNING issues after upgrading packages (SOLVED)

[Eric Haszlakiewicz <erh%nimenees.com@localhost>]

I recently upgraded all of the packages on my NetBSD 6 system using the 
"pkgin full-upgrade" command and ran into some problems after that finished.
It appeared to run without errors, but trying to start programs like firefox
or xzgv produced this:
 
(firefox:10231): Gtk-WARNING **: Error loading theme icon 'gtk-go-back-ltr' for 
stock: Unrecognized image file format

(xzgv:10732): GdkPixbuf-WARNING **: Error loading XPM image loader: Image type 
'xpm' is not supported

It seems that this was because several files didn't get updated properly when
the packages were installed.  I fixed it with this sequence of commands:

 update-mime-database /usr/pkg/share/mime
 pango-querymodules > /usr/pkg/libdata/pango/pango.modules
 /usr/pkg/bin/gdk-pixbuf-query-loaders > 
/usr/pkg/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache


pkgin was at version 0.6.3.1 when I started.  I found errors like this
in /var/db/pkgin/pkg_install-err.log, even though the pkgin output
claimed there were only warnings:

...
---May 11 12:49:46: installing gdk-pixbuf2-2.26.5nb2...
Shared object "libffi.so.6" not found
---May 11 12:49:46: installing cairo-1.12.14nb1...
pkg_add: A different version of cairo-1.12.14nb1 is already installed: 
cairo-1.12.14nb1
...

I suspect that was the cause of the problem.  Perhaps pkgin didn't install the
packaged in the proper order.  
I don't know what to do about that, but I'm hoping this email will help anyone
else that might have a similar problem.

Eric