Vid Card problem x_x

I’m trying to install the following video card:

on a box running 98, and with a 300watt power supply.

Despite the system requirements mentioned on the products page, there is an nvidia driver that runs that chipset for 98 (, which seems to be working well enough. This card, however, is rather strange in that it requires more power via a cord on the back. Without that cord, and being inserted only into the AGP slot in the motherboard, the fan runs on the card, but the monitor plugged in will not turn on at all. However, it seems to work fine [to a point], with the cord in.

After replacing the old card with this one, I booted into safe mode and installed the new driver, and everything seemed to work fine. It asked to restart, so I did, and win loaded normally. When it was up, it brought me through an ‘add new hardware’ wizard for the monitor, and then after that was done, all the standard programs that load at startup load, and then the screen goes black, and the light on the monitor is like that of when the computer is turned off. The computer is on, however, and all the fans and everything seem to be running normally. This happens every time I try to boot the box now, except in safe mode.

Any ideas what the problem might be? I suppose it could be the power supply, but that seems to be an extremely odd moment for the display to die–one would think that would happen either immediatly after turning the computer on, or immediatly when windows was loaded, rather than four or so seconds afterwards. I can’t think of anything else the problem might be.