2.6.3 isn't a solution for me either.  UXA locks X (the keyboard and display locks during the gnome-session startup - the mouse cursor works however).  I think the BO aspect of the xserver-xorg-video-intel problems may be out of the way.

This log was generated when I tried EXA with NoLegacy3D:

X.Org X Server 1.6.0
Release Date: 2009-2-25
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-19-server i686 Ubuntu
Current Operating System: Linux bang 2.6.28-10-generic #33-Ubuntu SMP Tue Mar 17 12:27:50 UTC 2009 i686
Build Date: 07 March 2009  02:18:57AM
xorg-server 2:1.6.0-0ubuntu1 (<email address hidden>) 
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: [    0.011339] (--) probed, [    0.011360] (**) from config file, [    0.011375] (==) default setting,
        [    0.011390] (++) from command line, [    0.011404] (!!) notice, [    0.011418] (II) informational,
        [    0.011433] (WW) warning, [    0.011447] (EE) error, [    0.011461] (NI) not implemented, [    0.011476] (??) unknown.

[    0.011590] (==) Log file: "/var/log/Xorg.0.log", Time: Wed Mar 18 08:37:21 2009
[    0.028686] (==) Using config file: "/etc/X11/xorg.conf"
exaCopyDirty: Pending damage region empty!
error setting MTRR (base = 0xe8000000, size = 0x08000000, type = 1) Invalid argument (22)
 ddxSigGiveUp: Closing log


This is what I got from UXA without default options. (I can't use UXA with DRI off. X still locks with Legacy3D)

X.Org X Server 1.6.0
Release Date: 2009-2-25
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-19-server i686 Ubuntu
Current Operating System: Linux bang 2.6.28-10-generic #33-Ubuntu SMP Tue Mar 17 12:27:50 UTC 2009 i686
Build Date: 07 March 2009  02:18:57AM
xorg-server 2:1.6.0-0ubuntu1 (<email address hidden>) 
	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.
Markers: [    0.017446] (--) probed, [    0.017469] (**) from config file, [    0.017484] (==) default setting,
	[    0.017498] (++) from command line, [    0.017513] (!!) notice, [    0.017527] (II) informational,
	[    0.017541] (WW) warning, [    0.017556] (EE) error, [    0.017570] (NI) not implemented, [    0.017584] (??) unknown.
[    0.017701] (==) Log file: "/var/log/Xorg.0.log", Time: Wed Mar 18 08:28:57 2009
[    0.034666] (==) Using config file: "/etc/X11/xorg.conf"
get fences failed: -1
param: 6, val: 0
get fences failed: -1
param: 6, val: 0
[mi] EQ overflowing. The server is probably stuck in an infinite loop.

Backtrace:
0: /usr/X11R6/bin/X(xorg_backtrace+0x3b) [0x8134f0b]
1: /usr/X11R6/bin/X(mieqEnqueue+0x2d9) [0x8114ab9]
2: /usr/X11R6/bin/X(xf86PostKeyboardEvent+0xc5) [0x80d81c5]
3: /usr/lib/xorg/modules/input//evdev_drv.so [0xaf47a3db]
4: /usr/X11R6/bin/X [0x80c7dc7]
5: /usr/X11R6/bin/X [0x80b82ec]
6: [0xb7eef400]
7: /usr/lib/xorg/modules/drivers//intel_drv.so [0xb781b810]
8: /usr/lib/xorg/modules/drivers//intel_drv.so(uxa_prepare_access+0x64) [0xb7832574]
9: /usr/lib/xorg/modules/drivers//intel_drv.so(uxa_copy_n_to_n+0x2db) [0xb78349fb]
10: /usr/lib/xorg/modules//libfb.so(fbCopyRegion+0x1d6) [0xb7725796]
11: /usr/lib/xorg/modules//libfb.so(fbDoCopy+0x4a3) [0xb7725d73]
12: /usr/lib/xorg/modules/drivers//intel_drv.so(uxa_copy_area+0x98) [0xb78346c8]
13: /usr/X11R6/bin/X [0x8182172]
14: /usr/X11R6/bin/X [0x815564d]
15: /usr/X11R6/bin/X [0x81567a8]
16: /usr/X11R6/bin/X(Dispatch+0x33f) [0x808d5af]
17: /usr/X11R6/bin/X(main+0x3bd) [0x807231d]
18: /lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe5) [0xb7b08775]
19: /usr/X11R6/bin/X [0x80717d1]
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.
[mi] EQ overflowing. The server is probably stuck in an infinite loop.

For reference:
00:02.0 VGA compatible controller [0300]: Intel Corporation 82865G Integrated Graphics Controller [8086:2572] (rev 02) (prog-if 00 [VGA])
	Subsystem: Dell Device [1028:0151]
	Flags: bus master, fast devsel, latency 0, IRQ 16
	Memory at e8000000 (32-bit, prefetchable) [size=128M]
	Memory at feb80000 (32-bit, non-prefetchable) [size=512K]
	I/O ports at ed98 [size=8]
	Capabilities: [d0] Power Management version 1
	Kernel modules: intelfb