Dual Core Overheating

i've noticed when using speedfan that one of my core is running well over what it should and under load its extremely high.

amd am2 +6000

core 1 @ 30c
core 2 @ 54c(idle)
core 2 @ 70+(load)

i'm using high quality paste and heatsink/fan combo.
i'm not new to building computers but this just hits me as wrong.

any thoughts or ideas?

cheers


p.s. i'll post system specs if need be.