Is the display card listed below?

AST Power Premium 486 with VGA motherboard.
ATI Ultra Graphics Pro (local bus).
COMPAQ Qvision.
Dell 486/20 with VGA on motherboard.
Diamond Stealth64 video driver.
Genoa 7900 MM card.
Hercules Dynamite Power VESA with ET 4000 chipset.
MACH32.
MATROX MGA video driver using 1024 x 768 resolution.
NEC 2A.
Oak VGA card with 640 x 480 x 256 colours for 286 or higher processor.
Orchid Fahrenheit 1280 card using Microsoft Windows version 3.1.
Speed Star 24x.
TIGA 1024 x 768 x 256 small fonts.
Trident 8900C.
Number 9 Reality 332 video card with Hawkeye driver.

If it is, maybe try another display card.

Jeun.