I just sucessfully installed Zephyroth Leopard 10.5.2 AMD.I already set Mac partition active but It doesn't boot without DVD inserted.With DVD inserted it still stuck at apple white screen as the picture I attached below.

My spec:

CPU AMD Athlon X2 4200+
Mainboard J&W JWTN61S nForce405 + Geforce6100
Harddisk SATA 160Gb
Ram 1Gb
DVD rom