You may have to go into the BIOS to enable those RAM slots, or disable the others. Whatever the BIOS calls for, although this kind of thing is usually automatic. You should get into the BIOS and check it out. It's also possible there may be jumpers to control this.
But, you may have a problem with that PC3200 as the chipset is designed to use PC2100. Now normally faster RAM should run slower just fine. But PC133 and PC2100 both run at 133 Mhz so I'm guessing that faster RAM is not going to work. These boards that will run dual types of RAM can be fussy.
Without being familiar with that chipset, this is just a guess. Hopefully you have the manual that came with the board and can look at that. As I said, you should poke around in the BIOS and see what you can learn there. There may also be a newer BIOS version available that may solve this issue.