2670 QM - BCLK change and multiplier bugged?

Some time ago I wanted to check how much more qould I get from my CPU. Changed the BCLK to 103.3 and preety much left it at that. After about a week thought that there's actually plenty of power in it for my humble needs and after some 3dMark Vantage tests (just for the satisfaction ;-)) I reset it back to default values.

All worked well for about 2 weeks. Then when playing Witcher 2 I've noticed long loading times and what seemed like poor performance. Checked hwinfo64 and CPU speed was about 1.8-1.9 GHz on each core. CPU-Z showed that the multiplier was only going up to x19 and no turbo was working at all (though the temps would not go higher than 66'C so there's a plus ). Also Core VID would only reach ~0.95 V rather than the default 1.221 V.

I've tried Intel Processor Diagnostic Tool and it claimed everything works fine.

Tested CPU with windows experience index (just to get confirmation that it's not just wrong sensor readings) and went down form 7,5 that 2670QM should get to 7,3.

Another thing I tried was the XTU (version 2.1, as the later ones would not allow me to change anything). It claimed that the multiplier was set to x22 (just as if it loaded 2670QM default values without confirming that they actually work). I thought that perhaps if I change it manually to x19 (which I knew was true anyway) and then back to x22 it may work.
It did not and got stuck at x19 - claiming that 'some settings could not be applied' after the reset.

I also tried reinstalling windows though it didn't work either. I also reset the bios by reseating the CMOS battery and this did finally work.

Does anyone have idea how it all got messed up like that? I couldn't find any other thread about similair case and looked all over the internet