Originally Posted by
elTwitcho
This is a lot more likely to ruin your cranks, don't do this. The bolt isn't breaking loose, the arms are settling on the taper. By re-tightening you're over-tightening the bolts.
From Jobst Brandt
That doesn't address what to do about "loss of bolt preload" though, lubrication of the threads maybe? I'll take my chances in cracking my crank, to forgo it rounding out and screwing me anyway.