[nordlys]

Try tinkering with the driver settings in catalyst control center. A safe rule of thumb is switch to "application controlled" everything that can be (like antialiasing) and switch off everything else. Dominions in particular didn't like the "catalyst ai" enabled, it garbled the game fonts for me.

ati is also known for screwed up opengl support, and I figure Dominions uses just that, so you may want to try various command line switches for dom3.exe:

-p --perftest Run a performance test and exit
-x --fastgrx Faster graphics (use 3 times for best performance (-xxx))
--renderpath X Use different optimizations 0-1 (0=good for low mem cards)
-V --novsync Disable vsync
--vsync Enable vsync
--noglext Don't use any OpenGL extensions
--noarcade Don't draw floating damage numbers
--nograss Don't draw the grass
--partamount X Max nbr of particles 0-8 (0=none, 4=default, 8=max)
--nolightfx No light effects in battles
--texqual X Texture quality 1-5 (default=3)
--treequal X Tree quality 1-5 (default=3)
--maxtexsize X Max texture size in pixels 32-4096 (default=unlimited)
--filtering X Quality of OpenGL filtering 0-3 (default=2)
--maxfps X Maximum nbr of frames per second (default=50)
--fps X Aim for this nbr of frames per second (default=20)
--nopopups No helpful popups
-f --nofade No fade effects
--fade Use fade effects
-a --noanimback Don't use animated backgrounds
--animback Use animated backgrounds
-r --res X Y Set screen resolution / window size (default=1024 768)
--opacity X Set gui opacity 0 - 100
--gamma X Set gamma function (brightness) 0.1 - 5.0 (default=1.0)
-T --textonly Use this with --tcpserver to get graphicless server
--zbuffer X Try to use a depth buffer of X bits per pixel (default=16)
--bitplanes X Try to use a color depth of X bits per pixel
-u --fullscreen Use the entire screen
-w --window Run Dominions 3 in a window

some of these may help.

and of course, try using the -ddd command line switch to log debug info in case this is not related to v-card altogether.