Works fine on my £25 ebay special GeForce GT710, although I do have to use linux.
Seriously, take a look at the graphics modes the card supports. You need 1024x768 for vanilla, but the widescreen mods include a d3d9.ini or similar file with lines like:
[ENGINE]
DisplayWidth=1920
DisplayHeight=1024
Refreshrate=false
Your display has to be able to support this mode. Setting Refreshrate false means you do not have to match the refresh rate. There's usually a tweaking app that allows you to mess with the display modes and even cook your own.
As a last resort you can edit [SH3 directory]\data\Cfg\Main.cfg
Fullscreen=No
The vanilla game should then start in a window.
...or it could be something else
