I think since Duron use FSB 100Mhz it will not have any problem as
long as you have the multiplier setting on the bios, so in order to run Duron 1200Mhz
you have to have Multiplier setting 12x100 FSB.
But you have to reinstall the OS since Duron Morgan has SSE function otherwise it still will
work just fine but the SSE is not functioning yet.
if you plan to Use Duron 1300Mhz, I'm not sure if KT7A has multiplier 13 on the bios
or if not probably you can flash the bios
peace