ECS K7S5A(SIS 735) confliting with Nvidia Gforce2

First of all I hate to burst your bubble but that is not a great video card. Secondly, disabling AGP 4x in bios does not disable hardware acceleration it merely runs in AGP2x mode. Third, you fail to mention what drivers you are using, what size power supply, etc etc. Please list your current OS, dx version, nvidia driver revision and any thing else that may be relevant. My ECS board runs flawlessly with a gforce2 ultra. Now, you very well cold have a bad board, but more likley the symptons you describe could be a result of being underpowered.

It's not what they tell you, its what they don't tell you!

You must first install your graphics card drivers and then AGP drivers for Your MB. You also need to run DMA98.EXE which is contained in directory \win9x\sisfiles of the agp driver package, to make sure that all of the drives are in the correct DMA mode.
Shortly, please read the K7S5A FAQ at ocworkbench //forum.ocworkbench.com/ocwbcgi/ultimatebb.cgi?ubb=get_topic&f=4&t=001477
It`s very useful.

Running an MX400 at 2x AGP shouldn't cause a problem. The GPU can't realy handle a full 4x of data anyway.

Try disabling other AGP features, like AGP Fast writes, Read Sync, ect.

Also, try newer or older drivers of the Detonator drivers.

Do you get the same problem if you try to use the manufacturer's drivers?

RAM Disk is not an instalation step.

check out the psu faq in ocworkbench. i use to have an lc-250w and there ampage sucked horribly.... now i'm an enermax user.

Hey Baby, I'll install YOUR RAM, if you boot my Hard drive!

You might want to consider going back to 21.83 drivers. I am told by EVGA that there has been troubles with the 23.11. I was having lockups and contacted them. They suggested I revert.....I did and no lockups anymore. Not sure if that is your problem but its a thought.