Hey folks, i'm not sure if this is the right forum to post, but my research has led me to believe that. If it should turn out that this i just forgot to switch on some obscure options, or it is actually the games' bugs, then feel free to move this thread.
I'm currently running Ubuntu Jaunty with stock kernel (2.6.28-15, x64) and opensource radeon drivers & graphics stack from the xorg-edgers ppa, on a 64-bit system with a Radeon X1600 w/ 256 MB RAM.
Openarena, compiz and the demos of ballistics and Postal 2 work like a charm, but the game that brought me to the whole thougt of playing on linux is hanging
When i try to start the demo version of LGP's X2 port, i see the loading screen, then it turns blank, i hear the sounds of LGPs "intro movie", then silence and blank screen for 1-4 seconds, and then the game segfaults with a message like this:
x2-demo 1.4.05, built for i386
Segmentation Fault: What do you mean mind the asteroid? What astero

This is a BUG, please report it to http://support.linuxgamepublishing.com
Stack dump:
	/usr/lib32/libGL.so.1 [0xf73dd9ad]
	/usr/lib32/libGL.so.1 [0xf73dd5ce]
	x2_demo [0x80f51b6]
	x2_demo [0x80b7d87]
	x2_demo(vfprintf+0x2aed) [0x805195d]
	x2_demo(vfprintf+0x3830) [0x80526a0]
	x2_demo [0x81009cf]
	/lib32/libc.so.6(__libc_start_main+0xe5) [0xf7cb5775]
	x2_demo(XMapRaised+0x31) [0x804ff91]
for two times in my hours of random trying, i achieved to see the following loading screen before the segfault. LGPs testtool gives some interesting results, though:
 Testing installation... OK, installed at /usr/local/games/testtool
Base system Test
Testing architecture of system... 64 bits
Testing system CPU... 2794MHz
Testing CPU flags... MMX SSE SSE2 
Testing system memory... -298MB

Graphics Test
Looking for OpenGL library
Rejecting /usr/lib/libGL.so.1 - wrong architecture
Rejecting /usr/lib/libGL.so.1.2 - wrong architecture
Accepting /usr/lib32/libGL.so.1
  Card detected as DRI R300 Project Mesa DRI R300 (RV530 71C3) 20090101  TCL
  Direct Rendering: No
  Card memory detected as 256MB
  Card antialiasing level 0x
  Card anisotropic level 16x
  Card shader level 2.0
note the "direct rendering: No", whereas glxinfo returns
wirrbel@Datenschaufel:~$ glxinfo | grep direct
direct rendering: Yes
the syslogs also show nothing suspicious. Results are the same with stock graphics stack.
I think i have installed all the necessary libraries for running 32-bit apps on 64-bit systems, as well as all the old libraries required by LGPs installers (the script getlibs was a great help).
However, the demo runs fine (well, at slideshow-speed, but playable) on my EEE pc 4G, which has its integrated Intel graphic chip, an even older kernel and a 32-bit system.

My questions now are:
1. From my limited knowledge, a segfault often points to a memory problem. Could a custom compiled 2.6.31 kernel with enabled GEM/TTM bring help?
2. Could this segfault be a result of some animosity between 32-bit app and 64-bit system? i have 8 GB RAM installed, so perhaps there lies a source of trouble.
3. Could it be that the drivers' OpenGL implementation (somewhere at OpenGL v. 1.4 IIRC) just not yet fulfils the games' needs?
4. Might there be some arcane option in the xorg.conf or elsewhere, for direct rendering, shadowfb or something else? currently my xorg.conf has no customized entries.

Any hint is appreciated