Comment 12 for bug 665725

So, you need to execute this testheme.py:

chmod a+rx testtheme.py
./testheme.py

And if you're in the same situation as us, it should give you something like this (using Mint-X):

clem@gateway:~$ ./testtheme.py
Testing STOCK_DIRECTORY in 16px
<gtk.gdk.Pixbuf object at 0x28fe5f0 (GdkPixbuf at 0x2a11800)>
Testing STOCK_DIRECTORY in 22px
<gtk.gdk.Pixbuf object at 0x28fe640 (GdkPixbuf at 0x2a11850)>
Testing STOCK_DIRECTORY in 24px
<gtk.gdk.Pixbuf object at 0x28fe5f0 (GdkPixbuf at 0x2a118a0)>
Testing STOCK_DIRECTORY in 32px
<gtk.gdk.Pixbuf object at 0x28fe640 (GdkPixbuf at 0x2a118f0)>
Testing STOCK_DIRECTORY in 48px
<gtk.gdk.Pixbuf object at 0x28fe5f0 (GdkPixbuf at 0x2a11940)>
Testing STOCK_FILE in 16px
Error opening file: No such file or directory
Testing STOCK_FILE in 22px
Error opening file: No such file or directory
Testing STOCK_FILE in 24px
Error opening file: No such file or directory
Testing STOCK_FILE in 32px
Error opening file: No such file or directory
Testing STOCK_FILE in 48px
Error opening file: No such file or directory

Notice how it finds the GTK_STOCK_DIRECTORY but fails to load the GTK_STOCK_FILE icon?

You can switch your icon theme to another one and see that it all works (using New Wave):

clem@gateway:~$ ./testtheme.py
Testing STOCK_DIRECTORY in 16px
<gtk.gdk.Pixbuf object at 0x17e95f0 (GdkPixbuf at 0x1948cf0)>
Testing STOCK_DIRECTORY in 22px
<gtk.gdk.Pixbuf object at 0x17e9640 (GdkPixbuf at 0x191a8a0)>
Testing STOCK_DIRECTORY in 24px
<gtk.gdk.Pixbuf object at 0x17e95f0 (GdkPixbuf at 0x1944de0)>
Testing STOCK_DIRECTORY in 32px
<gtk.gdk.Pixbuf object at 0x17e9640 (GdkPixbuf at 0x192bc50)>
Testing STOCK_DIRECTORY in 48px
<gtk.gdk.Pixbuf object at 0x17e95f0 (GdkPixbuf at 0x19489e0)>
Testing STOCK_FILE in 16px
<gtk.gdk.Pixbuf object at 0x17e9640 (GdkPixbuf at 0x191ae30)>
Testing STOCK_FILE in 22px
<gtk.gdk.Pixbuf object at 0x17e95f0 (GdkPixbuf at 0x192bc50)>
Testing STOCK_FILE in 24px
<gtk.gdk.Pixbuf object at 0x17e9640 (GdkPixbuf at 0x1937a30)>
Testing STOCK_FILE in 32px
<gtk.gdk.Pixbuf object at 0x17e95f0 (GdkPixbuf at 0x19341e0)>
Testing STOCK_FILE in 48px
<gtk.gdk.Pixbuf object at 0x17e9640 (GdkPixbuf at 0x1937450)>

And here it finds everything....

... so let's see what's different between these two themes (in our case Mint-X and New Wave)...