Originally Posted by Schturman

How you installed N9QT ? via terminal as root or as user ? double click on file from filebox ?

I had the similar problem when I installed some apps from terminal as user and only reflash helped me..
but I forgot about this solution:

Code:

chmod -R +rx /usr/share/icons/hicolor/80x80

or 

chmod 775 /usr/share/icons/hicolor/80x80/