I did eventually get the motherboard to overclock -- but only a very little. The trick is to start small. Set the FSB to 205 in the CMOS setup, and then reboot. Voila! The cpu is running at 2050 mhz, according to CPUZ. You can then set it to 210, and reboot, and you have 2100 mhz. At 215 mhz FSB, the BIOS gives an error during POST and says it has reset the CPU speed (which indeed it has). If you start by overclocking at 210, it will ignore your settings, but if you start at 205, and then later go to 210, it will work. Of course, a 5% overclock (200 mhz to 210 mhz) is hardly worth the effort. There is a setting for the Vcore, but it only goes up to 1.35 volts (default is 1.30), and it simply doesn't help. Maximum overclock is still 210 mhz FSB (2100 mhz cpu speed).
I have ordered an Arctic Cooling Freezer 64 Pro from ChiefValue, and I'll see what temperatures are reported with that.
I am also thinking of buying a better motherboard, and dumping this one for $35. Anyone have a recommendation for a good AM2 motherboard that doesn't break the bank?