Wrong Application Icon

[give.away]

Greetings!

Problem: Shortcuts and applications show the "unknown application"-icon.

I already tried to delete "iconcache.db" and "Personalize > Change Desktop Icon > Restore". (I, of course, also tried to change then icon back by the conventional way.)

When I cange the colour depth, the correct icons are displayed. If I reset the original colour depth the "unknown application"-icon is displayed again.

Is there a better solution than reinstalling the complete application, which works? What causes this misfunction?

Thanks in advance!
GA

Additional Information
+ This seems to be the case only for "Mozilla Sunbird" and "Skype", though I think that is just a coincidence and could happen with every application under the "right" circumstances.