Just to make this clear: Recovery method IS NOT the F7 method.
F7 is the recommended method by Intel (press F7 during Boot, then use a stick or something)
However, previous Bios updates to SB boards with changes to ME didn't work, if not applied using the recovery method.
The recovery method requires unplugging, removing BIOS jumper, plugging in a 'bootable, fat-formatted' Stick with th BIO file, then booting.
Also it is not clear if BIOS updates work at all, if the BIOS was set to EFI mode.
I haven't solved the turbo boost cap problem but I've noticed that in most real world applications it doesn't have an effect. For instance in 3D applications or during OS operations I can keep the CPU frequency at 4.4GHz and it will stay there without issue. I'm attributing that to the fact that those uses don't fully soak all 4 cores (as you do in stress testing) and I'm assuming that something changed about the power throttling for TB in 0042.
I don't plan to chase the issue with Intel; it was way too much time and energy just to get them to acknowledge the original problem and a long wait to see a solution. I think the lesson learned (for me) will be applied next time I buy a motherboard.
Thanks for your Reply 10c! You helped a lot. I didn't think about that, to test the CPU under real world applications. So I did it. And gues what. I had a stable Overclock with use of 3 cores and CPU usage 60-70%.And all that with the value that was set in the BIOS/// It only dropped when the CPU was over 80% loaded and all 4 cores active. It does make sense, when knowing that:
1) DZ68DB is not that Overclock friendly
2) Has a light power regulator, which sort of "protects" the CPU and the Mobo under heavy load (many user reviews have stated this, by describing the speed drop in certain cases).
3) It's overclocking basics that: 1 active core reaches the maximum speed,but with 4 cores maxed is not that easy. And since the DZ68DB doesn't provide much options for overclocking then all makes sence. It seems that the new BIOS kind of drops the speed when all 4 cores are at 100% but this happens only with synthetic extreme benchmarks, in other words only in extreme situations.
In any case I am happier now and I can say that Overclocking DOES work!