System Environment:
--------------------------

--Platform:965
 
--Architecture(32-bit,64-bit,compatiblity):64bit 

--2D driver:git commit 24248097988775d62f6c416f2988e74d31c91cd0


--3D driver:git commit 32134b5508495fbb1d9fc2f844e22fbb082dcda6 


--DRM:commit b986d7d2c9090fc62c1853f62886dd124e8066c1


--Xserver:commit b1f3f42840ec01db417345a0740b59ad5e4471cb


--Kernel:
2.6.25-rc3

Bug detailed description:
--------------------------
startx , run the ensight.csh, it soon crash X .And anther Specviewperf case 'ugnx' also crash X , and they have the same backtrace . 


Reproduce steps:
----------------
1. startx
2. run case ensight 


Current result:
----------------
X crash 


Expected result:
----------------
run normally