Created attachment 27402 [details]
C-code to illustrate the bug. Trivial GL example.  

Enabling option "AccelMethod" "UXA" causes GL writing to front buffer to appear
in the wrong place. 

The attached code is a minor modification to the standard OpenGL quad.c example.
Instead of writing to the back buffer, it writes to the front this illustrates the problem.

The writes to the front buffer appear in a region at top left (0,0) which never moves. Under pure metacity window manager, the window that pops up has decorations etc and can be dragged around, but that is not where the drawing occurs. The area drawn resizes in accordance with changes in the window size. But it never moves from the top left.

Without UXA enabled, correct behavior is observed. [With metacity, that is. Compiz is another whole mess, that I'm not getting into here!]

Fully updated Ubuntu Jaunty x86_64:

X.Org X Server 1.6.0
Release Date: 2009-2-25
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-15-server x86_64 Ubuntu
Current Operating System: Linux tp400-64 2.6.28-13-generic #45-Ubuntu SMP Tue Jun 30 22:12:12 UTC 2009 x86_64
Build Date: 09 April 2009  02:11:54AM
...
(II) Module intel: vendor="X.Org Foundation"
        compiled for 1.6.0, module version = 2.6.3
        Module class: X.Org Video Driver
        ABI class: X.Org Video Driver, version 5.0
(II) intel: Driver for Intel Integrated Graphics Chipsets: i810,
        i810-dc100, i810e, i815, i830M, 845G, 852GM/855GM, 865G, 915G,
        E7221 (i915), 915GM, 945G, 945GM, 945GME, 965G, G35, 965Q, 946GZ,
        965GM, 965GME/GLE, G33, Q35, Q33,
        Mobile Intel® GM45 Express Chipset,
        Intel Integrated Graphics Device, G45/G43, Q45/Q43, G41
...
(==) intel(0): Default visual is TrueColor
(II) intel(0): Integrated Graphics Chipset: Intel(R) Mobile Intel® GM45 Express Chipset
(--) intel(0): Chipset: "Mobile Intel® GM45 Express Chipset"
(--) intel(0): Linear framebuffer at 0xD0000000