trouble with wacom cintiq and gimp

I posted the same question on the gimp forum without success so I guess I try here too.

I cant have my cursor matching the position of the brush in extended screen and if I try to use clones screen or only the screen of the cintiq, gimp go crazy and color randomly change and other strang things apend.

I tryed to switch from display to window mode but then I have absolutly nothing as I supose the window in question isent the gimp window.

Any idea?