compositor settings

[Sergey Manucharian]

Hi folks,

I'm using xfce compositor and have found it useful in many cases.
But it makes working with Gimp almost impossible if I use transparency
for inactive windows.

My question: is it possible either change the "compositing" features
"on the fly" or "dedicate" a setting for a particular window?
I understand that it is possible in principal, but could it be applied
to xfce window manager?

Cheers,
Sergey