Created attachment 101389 [details]
screenshot of the problem

This is an issue with the hal volume monitor backend in gvfs.
I think it might be due to it using a bunch of new icons that are not yet availible though.

First, see bug 506532 for a request of these icons. 

Second, I believe that the code using gvfs should be able to use the fallback code in

http://library.gnome.org/devel/gtk/unstable/GtkIconTheme.html#gtk-icon-theme-choose-icon

such that I don't have to manually pass e.g.

 media-optical-dvd-rw-plus
 media-optical-dvd-rw
 media-optical-dvd
 media-optical
 media

instead of just media-optical-dvd-rw-plus to GThemedIcon. Or maybe GThemedIcon itself should cope with the fallback names. Matthias, Alex?

david: 
I don't agree. 
Using the default fallback approach enforces that specific order, meaning you can't for instance have another alternative that is used before media-optical. 
Fallbacks is also not what you want in all cases of themed icons, and GThemedIcon is a generic abstraction not just used for media icons.

(In reply to comment #4)
> david: 
> I don't agree. 
> Using the default fallback approach enforces that specific order, meaning you
> can't for instance have another alternative that is used before media-optical. 
> Fallbacks is also not what you want in all cases of themed icons, and
> GThemedIcon is a generic abstraction not just used for media icons.

Your response is hard to parse but here are some questions.

 - Why do think that fallback mechanisms is restricted to just media icons?

 - It seems to me that it's a pure implementation detail, at rendering
   time, that a fallback icon can be chosen right?

 - Seems weird to encode such an implementation detail into GThemedIcon
   don't you think? I mean, if we did encoded media, media-optical, ..
   into GThemedIcon why even bother with GTK_ICON_LOOKUP_GENERIC_FALLBACK
   in the first place?

More questions than answers, sorry.

Indeed, I don't propose to use GTK_ICON_LOOKUP_GENERIC_FALLBACK at all. Its not good enough for a generic fallback system. Its not restricted to media icons, but it is restricted to things that only use that form of fallback.

As an example of a case where the generic fallback isn't good enough, consider the extensions of mime icons that have been discussed for a long time on the xdg list.  This would add, for each mimetype a "generic" icon or type, such that msword documents have a generic type of "wordprocessor document". When picking the icon for such a type we'd pick the precise icon based on the msword mimetype, but if that fails we want to look up the generic icon before any use of the generic version of the msword mimetype.

There are probably also cases where you rather have no icon if the listed one doesn't exist rather than accidentally picking a fallback icon (after all, GTK_ICON_LOOKUP_GENERIC_FALLBACK is an option, not the default).

Fixed now.