Temperature Difference?

Hello.. i have a Soltek SL75DRV5-E mobo.. and an Athlon XP 1600+ with stock cooling.. i am having come confusions
the mobo monitor shows the CPU diode temp always 30 degrees greater than the CPU socket temp.. i wanted to know why is there such a big temp difference. For example if the CPU socket temp is 45 than the Diode temp is 75.
Here is the PIC...



My Friends told me that i might have a "Dead Diode" .. i wanted to know if that is possible... and now what is my "REAL" CPU temperature.

what i know that the cpu deode temp is alwais 12~15c higher than the socket temp in full load application
but to get 30 c deference is one of two:
1)motherboard monitor has confict with other software. never run it with other temp monitor utility
2)your heat sink is not seatting proprly

for (1) The Bios shows the same temps...
(2) I'll check out the Heat Sink..