This motherboard is based off the SIS 661FX Chipset. You may not have installed SIS's AGP drivers. I would first make sure that you remove any videocard drivers, then go to
http://download.sis.com/
Download the drivers for The Agp. Its listed under chipset.
The reason it may not be happening with the ELSA Gladiac 920 is because its only a 2x/4x AGp card, whereas the Radeon 9700 All in Wonder is an 8x card. Hopefully this solves your problem! Keep us posted
