Stop the presses. I had the same problem and when I searched, leaking valve seals was the number one "answer". However, the number two answer cost me $5 and worked. I replaced the PCV valve on the passenger side valve cover. It fixed my issue.
The concept being that as the motor cools, the PCV valve should let the crack case vent but instead, the drop in temp creates a suction that pulls the oil past the seals. I'm not saying that your valves aren't bad, but mine hasn't smoked since and I believe in trying the $5 fixes before the valve job.