frozen Xfree4.2

Hi everybody

First, I want to thank you for the binarie release of Qt. I think it's a 
great thing for QNX users.

Nevertheless, I have a problem to resolve before be fully operational with 
Qt. 
Regularly, my Xwindow fall in an freeze state. I only have the reset button 
solution to restart the system (CTRL+ALT+BACKSPACE doesn't work). There is 
nothing special in /var/log/XFree86.0.log.

Is there a diagnostics procedure I have to do to isolate the problem ?
Do I have to recompile XFree42 to make it works correctly with my system ? 
(Is the source package for QNX available in OpenQNX ? )

Thank in advance for your response !
-- 
				Institut Albert Bonniot
Johan CARDON			Faculté de Medecine de Grenoble
Laboratoire IMAG/TIMC/GMCAO 	Domaine de la Merci
Tel: +33 (0)4 76 54 95 05		38706 La Tronche Cedex