Just about all whom have responded have said your temps look good from their experience seeing 100's of these posts like yours over many different brands of motherboard. That about covers temps.
is it possible that my motherboard is reading the temperatures wrong? = I doubt it seriously.
or is it a problem with my temperature monitoring software? = Not likely since your temps with the exception of that AUX temp, seem mighty good overall. No software is clinical or scientic grade. Not meant to be. The majority of cpus have an inbuilt shutdown circuit if the temps reach beyond the point at which damage would occur.
also, can anyone tell me what part of the mb the CPUTIN is? Northbridge or is it the actual CPU SOCKET? = This is greatly debated without a 'super' defintitve answer. And is subject to change depending on some variables. The mobo maker CAN have that temp reading come from a socket sensor IF the cpu was unable to produce such signal. There is no way to know such since in the field we do not have the equipment for such testing nor are we going to be privvy to intellectual property to give us testing criteria. It really does not matter in the overall scope of things if the temp is not showing too high. Yours does not.
Just trying to get a feel for what each temp corresponds with on the mainboard. = To most viewing your thread, your temps 'feel' pretty darn good.
Your main problem will be just like mine from now on, and that is we did not buy a 1090T or 1100T Thuban processor while they were still available and had not dried up in the market place. They were multiplier unlocked cpus and did not rely on clocking the heck out of the FSB/Cpu Frequency which does need a very good motherboard. Just raising a cpu multiplier for increased clock speed put most of the strain on the Cpu, but clocking by FSB/Cpu Frequency puts a lot of the load on how well the motherboard is fit for FSB clocking.