I only noticed this after getting the info to trigger directly from the dist and wiring it up. So I swithed back to the stock Orange box and got the same result. I switched back to the Jacob's and it's always the same. Check the timing cold = good, check the timing at operating temp = wierd. I wish I had a way to convert a video to the computer, I would post it for all to see.
On a side note, the Orange box retards my timing almost 8* at high rpm the piece of junk.
Maybe
oil pressure or something as I would thing heat would retard everything at all rpm.