Hi all,
Regarding stability problems, i always had them, particulary in summer (k6-2 heats too much),. I have an old 8 Mb ATI Rage card.
I have discovered that, lowering X resolution to 640x480 or less (changing the XF86Config file, not in the game) increases greatly Vendetta's stability, due to less mem transfers through AGP thanks to the freed card mem, i think.

Hope this help's somebody.

Yes - if you dont have that good a gfxcards the X server settings are really important for game performance. It's a good idea to drop down colors and resulotion, maybe even run the X server only with vendetta running. I've had fine results using that on systems, especially with little memory...
One do that by editing the '~/.xinitrc' and comment out anything written there, and adding the line:
exec /usr/local/bin/vendetta
EDIT: To start X normally again, just remove the line added and uncomment those commented out =)

Also...

Running vendetta windowed with an xterm tail -f ~/.vendetta/errors.log helps too. This prints all the stuff you miss =D

Right now i'm running X alone to play Vendetta, with no window manager.
To avoid changing XF86Config and xinit i'm using a little script from console mode (in .vendetta directory):

#!/bin/sh
X -xf86config XF86Config.game&
sleep 2
./vendetta

Note that i have another XF86Config file ("XF86Config.game") in /etc/X11, with the settings for vendetta (max resolution available 640x480, 16bit color, 85Hz)

Best regards.

startx -- -layout Games

Check out layout functions in X 4.x series, very handy.