First! How about opening the case and looking to the board itself?
Second ! Your Banshee is PCI or AGP?
Do you have a AGP Slot? If you don´t you , might be using a board with a i810 chipset!
If you have a AGP slot , any graphic card will work!
P.S:The AGP slot is th brown one! Almost at the middle and the first of the slots!
Better burn in Hell with some company than freeze in Heaven all alone