Are you sure you don't have a RAM problem? Is it all the same brand? What brand is it? What size sticks and in which order of loading?
52C isn't in the critical stage for a 1.4. AMD finally stated that anything below 65C is fair game. For a long time AMD had a ceiling of 72C.
As for the Thermal Paste Arctic Silver is the only way to go. And a thin layer at that, only on the chip-die. IMHO I don't prefer to use the thermal pad. But it has to be taken off with a thumb nail prior to using a thermal paste. Using both at once is a no-no.
The 1.4 can be a bear sometimes about which BIOS it likes to play with. And the very latest version isn't always the one that works best.
Are all your drivers XP compatable?
......Indecision may or may not be my problem......
...... Kickin' A Rock....
It ain't over 'till the Fat Lady sings.....