SuperJoker: What operating system are you using? Just the other day I found a bug within XP that was causing some of the missing core issues that have been a RealTemp problem for various versions.
In the About box of RealTemp, what does it show for the 3.30 version? Right click on the title bar to find the About... option. There was a big bug in 3.30 RC12 which I quickly removed from my site within about 12 hours but other sites got a hold of it and spread it far and wide. Try the 3.30 RC11 version and let me know if it finds your missing cores. I haven't heard any complaints about that version.
http://www.fileden.com/files/2008/3/3/1794507/RealTempBeta.zip
The QX processors have a few unique features. Hopefully if I send you a PM you can work with me to get RealTemp working correctly on your CPU. I wish I had access to a few QX CPUs but I don't.
RejZoR: On 99.9% of the CPUs I've seen, core 0 is the most accurate core for reported temperatures. It's almost as if Intel puts a little more effort into calibrating that one and uses the correct TJMax for that core. If I only wanted to look at one temperature number, I'd look at that one. I'll put your suggestion on the things to do list. The bloated RealTemp Settings window needs to be broken up into a few different windows controlled by a tab similar to CPU-Z for easier access. Once I find everyone's missing cores, then I can do this and add a few more features.