xorg 7.3 does not work

[Magicloud Magiclouds <magicloud.magiclouds@gmail.com>]

Dear all,
   I installed a new box yesterday with debian sid, which is fine. Then 
I `apt-get install xorg`, after I configure xserver-xorg as usual, 
`startx` failed, with message 'xinit: Server error.' and nothing more.
   I installed another box this morning, still the same.
   While another box which had xorg 7.2 and upgrade to 7.3 yesterday, 
works fine.

Thanks.