xorg multiseat xgl

[duportail]

I don not know if this is a xorg issue but I am building multiseat systems and 
in Ubuntu feisty all goes well,but in the new gutsy the system will not work.
On these multiseat system I am starting an underlaying xorg server and on each 
screen I start an xgl session.
In feisty there is no error,but in Gutsy the xgl sessions will not start 
because of the folowing error:
Cannot get exclusive access to the keyboard.
Is xorg taken exclusive access of the keyboards?
Can I start X in a special way to prevent this error?

dup