AMD Athlon 64 X2 5400+ clock ratio not what I set it

[instantkarma]

I have a Gigabyte GA M55plus S3G motherboard with Award Software BIOS and MIT (Motherboard Intelligence Tweaker) and just got a new Athlon 64 X2 5400+ Black Edition. I've been trying to set the multiplier at higher than default (cpu-z says that is 14x) with a 200 MHz Bus speed. I tried 15x and 16x and CPU-z detected no change; at 17x the screen went black and I had to clear the CMOS to get it working again. I've tried AMD Overdrive but am getting "not detected" errors. My BIOS version is over two years old, could that be the problem? What else could it be?

 

[roadrunner197069]

Update the bios, then OC from Bios.