* DDR2 1066 is supported with combination of AM2+ processors and DDR2 1066 memory modules, please refer "Memory Support List" for detail memory support information.
So here are my questions:
1. Is it normal for the system to not even be able to boot into BIOS in this situation?
2. If so, is there any way to get the system to boot into BIOS without having to either get new RAM or new CPU? People have said that 1066 is just an overclocked/unstable version of 800...so maybe it's possible to "underclock" it back to 800 if I can get the system to boot into BIOS?
^ Yes, boot with only 1 stick. If this works, you can get in and set the voltage, timings, speeds, etc to make all 4 work correctly. You may have to up the voltage slightly beyond spec, or loosen the timings to get all 4 sticks to work.
You know it would have been far better to buy 2-2gig sticks, right?