Unable to resize some Gtk applications

[Nikos Chantziaras]

I am unable to resize windows of some Gtk (or Gnome) applications. 
Nothing happens when I place the mouse on the edge of window. No resize 
cursor.

The windows where this happens do not seem to have standard window 
decorations. They do have min/max/close buttons, but that's it. I 
believe this has something to do with "client-side decorations."

How do I fix this?