Here's what better not to do: Use like 7 years old heat sink paste on yer brand new processor:
So, I cleaned it up. The only paste I had left was the stuff already applied on the heat sink of a brand new cooler... scraped it off, applied some to the CPU and some to the original cooler... all is good. On load it now runs at 68C, instead of 75C ... Have ordered me some fresh stuff though... Tomorrow I shall pull the stuff apart again, and put some of it on... well, if this thing lasts in this setup that is.
Oh well...