Welcome to WebmasterWorld Guest from 188.8.131.52
I'm using Firefox.
Apparently, https pages using a base tag and a .htc file will cause an error in IE (new one to me). Since my product pages do not contain advertising or a base tag and my content pages contained both, I mistakeningly assumed it was due to AdSense. Solution, removed base tag and all is well.
I wonder if this is an unreported IE error or for that matter an error at all.