3rd monitor

3rd card locks up my system

ok, ive been looking all over the net for some sort of forum devoted to multi-monitors, and this was the best ive found as of yet, im hoping you can help me out...
ive been running dual monitors for years and would love to go to three, but while still having the universal compatability of nvidia cards and without the pricetag of a matrox...plus its convenient i just happen to have all the parts i -should- need laying around
heres some of the basics of my system:
asus a7v333 moboard, 1agp 6pci, athlonXP 2000, 500watt power supply, 786mb DDR, etc, running win2K

my current setup is an AGP geforceFX5200 for my main and a PCI voodoo2 for my secondary (vintage i know, but ive never had a problem with it, now or with any previous primary cards)
thing is, i have plenty of monitors laying around and i have an extra PCI geforce2 MX...problem comes when i plug it in an empty slot and boot, itll start up windows, but then after the win2k loading screen it brings the desktop up on the secondary monitor (the 3dfx), the third monitor is blank except that the right half of the screen is solid green, and the mouse moves reeeally slow and choppy...none of the programs tho, they run normally, but the mouse seems to have a framerate of like 2fps (its a usb mouse if that makes any difference)...so i open display props, the second monitor is set as primary and the other two are switched off, so i swap it back to the way it was without problems, (even tho it takes really long with how the mouse is acting) but when i enable the third monitor, it just blanks out the second one and never does anything else (system is locked up at this point)

id love to go to three, but i keep running into this problem, and as usual there are no faqs or anything out there that cover this problem
can anyone help a frustrated man gain his third eye?
I'd suggest that there is a conflict between the two G force cards. Try any make other than Gforce PCI , or more explicitly, something that has a different chipset to the AGP card.
I ran, a long time ago, an AGP card ( can't remember which chipset) + 2 Voodoo cards on PCI with win2K so I know that works!