Alright, I'm having a consistent problem now. Whenever I install a program there is blank icon in menu, be in XFCE or GNOME. Icon is empty. I've had this problem with Firefox, Thunderbird, and now Crossover. I have to go an edit .desktop file and specify explicitly icon location. It appears that icons in hicolor theme where they are placed by default are not read.
I've tried Adwaita and gnome themes, same thing.
What's happening and how to fix it?