this is the last time i will explain this.
your motherboard will not fry in the 40s celcius. if it could fry that easily. we would be hearing about motherboards having a meltdown on a daily basis.
your intel processor is using speedstep. running 1600mhz on idle and running 2400mhz on load. this has nothing to do with front side bus (FSB). the processor will get hotter when it is on load and in use. also, your harddrive temperature will be raising when it's in use. so both of these factors or any other factors could affect your overall motherboard temperature.
just make sure you have enough air flow in your computer case and everything should be running smoothly. also, motherboard sensors are not 100% accurate. it could be displaying a few celcius higher or lower than what it really is.
your computer seems perfectly normal. just leave it at that.