Thank you for asking. I just tried to export a page with PDF to MHT file. I got somewhat different result - the page was simply blank. MS IE asked me if I want to enable to ActiveX when I clicked on the link to PDF in MHT. I agreed and got nothing - no further question, etc. It looks like not all ActiveX controls (incl. Adobe Acrobat) are not very compatible with MHT.
Best regards,
Oleg Chernavin
MetaProducts corp.