Tom, I know that you have been in the business for some time, however, have you checked the deck surface? Copper gaskets required a different finish than the one used for conventional head gaskets. I have used brush-on Hylomar ins lieu of the spray-on. In addition to the gasket, I also apply it to the deck and head surfaces and let it skin.
there is a product from gasket Works that also works great; it is P/N P/5
Other products I have used is Mopar P/N 04318035 Spray Gasket Sealant, Yamaha Bond #4, or Pliobond or 3-Bond #1194. The last three adhesives are used to seal the cases of motorcycle and Porsche engines.
One consideration also is the cooling system. When you use copper gaskets, you have to change the radiator cap rating.
Gasket Works has a great section about installing Copper gaskets at the following link:
http://www.headgasket.com/preinstall.html