Well I've decided to give back the cpu to my boss and use it in a client's system.

I'm gonna wait on this. My system just isn't stable at default settings either, so bios update is awaiting.

As for this batch? I don't know, but it looks like a lot of people are having to pump a lot of voltage into their E8400s to get above 4GHz or even 4GHz stable.

I will wait on this.

Cheers,
Mike