I am looking at the specs for your H8SMi-2 motherboard:
http://www.supermicro.com/Aplus/motherboard/Opteron1000/MCP55/H8SMi-2.cfm
I see that under Processor/Chipset the only processor listed is Quad-Core AMD Opteron™ 1000 Series. Is that the exhaustive list? Only this one AM2 processor is supported and no others such as the Athlon X2 64
4000+ for example?
With latest BIOS, it is compatible with Phenom and Athlon CPU.