VST Plugins outside their window

Why does Ardour-2.1 draws the VST plugins outside their Add/Bypass windows?

http://personales.ya.com/juanjavier_xxx/plugin.jpg

Is there a way to fix it? It happens just since I use Gnome.

Before I used Blackbox window manager. Everything went smooth. Any idea?

Simply changing the «Allow the window manager control the windows» setting in Winecfg Graphics tab solved the whole issue.

Juanjavier.