Indeed I was worried about the vDrop, I was just reporting the Load and Idle voltages for completeness sake.
The voltages I reported are for 0906 BIOS, though I got a similar vDrop on 0502 and 0602. I was supprised to see it on 0602 as well because most reports I've seen suggested it wasnt present.
If I set the voltage to 1.425v then reboot and go back to the BIOS and look in the Hardware Monitor it will report the voltage as 1.30v (ish, I'm at work atm).
So I am going to distrust the BIOS setting and instead believe the BIOS reading/CPU-Z/SpeedFan.
Also, the BIOS Hardware Monitor version of the vCore more closely matchs the stability I would expect when pushing the clock speed to 3.6Ghz.