I got your meaning the first time Just pokin fun at something that I've done as well. Just when you think you got it all wiped up, and clean, some how another smear suddenly appears. Same thing happens after I've greased something.
i have found that using the fiber type gaskets is what causes header bolts to loosen up. it will shrink and lessen the load on the header bolts allowing them to back out. lately ive been using the mr. gasket mls gaskets and have never had a bolt back out and when ive gone and rechecked them they are all still tight. before those were available i was using the earls pressure seal gaskets which used an aluminum frame with a graphite seal with the same results. the mls gaskets are reusable and easier than dealing with the graphite.