SDL: Could not initialize video
 

I'm running Slackware on a 486 with 80 MB harddrive.
The VGA controller is a Cirrus GD54M30, PCI bus. (1 MB VRAM).
It should be able to support 800*600, 16 bpp, but when I change to vga = ask in lilo.conf the modes I get is a list from 0-8.
When I 'scan', I get a list from 0-9 instead and the highest resolution is 154*something.

Is there any solution to this problem?
I want to run an application in 800*600, 16 bpp.

/zot