CPU and Chassis Temps

I've recently purchased a new Thermaltake Volcano 9 heatsink/fan for my AMD 1700+ XP processor on my machine. I took out the crappy old stock one that came with the processor and used some OCZ Ultra Premium Thermal Compound which I've been reading in some reviews is just as good as if not better than AS3. The motherboard is a MSI KT3 Ultra and I've recently attempted overclocking of my CPU, currently it is running at 1666.2 MHz, or stock standard for an AMD 2000+ XP.

For the last couple days since I purchased/installed the new sink/fan I've been monitoring the temperatures through MSI's own PC Alert III which came with my mobo. I also upgraded to the latest BIOS version recently as well. I've noticed something odd about the temperatures being reported (It is currently 25C in the room): While my system is idling my CPU temperature reads as 32C, which is much better than the temps I was getting before the new sink/fan, but the odd thing is that the chassis temp is the same as the CPU, sometimes the CPU being lower than the chassis temp by 1 degree. The load temps of my CPU jump to 48C which I assumed was due to the fact of my CPU core being a Palomino. The chassis temp under load was around 41C. I also have two case fans on the system, one intake, one exhaust. Oh, I forgot to mention that I checked the PC Alert III readings against the BIOS one's and they do reflect each other accordingly.

I was just wondering about the CPU/Chassis temp similarity, as this seems quite odd, but I thought might be due to the position of the sensor on the mobo, which is unknown to me. Could someone clear this up for me, and also is there any documentation for motherboards in which they show the position of the sensors? I've searched through the technical documentation on MSI's site but to no avail.