Help! Strange SiSoft results with my overclocked Duron

[axellaizza]

This is the first system I've ever built, so please
be gentle.

Specs: Duron 700 (Week 24), 9.5 x 105 = 997 MHz,
Kingston Value Ram, 128MB, PC100@133, 2-2-2
Asus A7V, 1.80 Vcore, Taisol Cek, 28~45C
Viper II, 32MB, 4X AGP
OS: Windows 2000 SP1

SiSoft Sandra 2000 Pro (latest update) result:

CPU Dhrystone: 43585 MIPS (This actually varies between 40000 and 70000 MIPS)
FPU Whetstone: 20157 MFLOPS

ALU Memory Bandwith: 457 MB/s
FPU Memory Bandwith: 588 MB/s

Any idea why the CPU/FPU stone scores are so strange?
Is it Windows 2000 or is it the CPU?

Thanks.

axell