X11 focus follow mouse with gimp

[Rémi Thébault]

Hi

Thanks to Yves, the Gimp is now installed but the focus don't follow  
the mouse.
I've installed the "Turn on X11 Focus follows mouse" supplied with  
Gimp.app but it quits right after being launched and has no effect.  
more embarrassing, the Gimp crashes, when I brush (it paints a little  
bit and then crashes).

If I can't fix this, I'll carry on using the Gimp in Ubuntu, I'm just  
fed up with rebooting every ten minutes

Any Ideas ?
Rémi.