Gdk-Error ** Fatal IO error 104

[Sylvestre Legrand <Sylvestre Legrand synelec fr>]

I get the following error by just playing with a spin button widget :
'Gdk-Error ** Fatal IO error 104' (server reset)
It append randomly, I have try to remove my code handler and I still  get 
the same error. I'm testing my application on a XFree 4.1.0 server with 
xinerama extension.