I understand that a caller to Rush Limbaugh's show today said pretty much the same thing about the layered nature of the document.
Please recall as well that the earlier CERTIFICATIONS of Live Birth posted on pro-Obama web sites in 2008 were detected by Polarik to be layered as well. So we have different documents but similar techniques of fraud.
Nathan Goulding of National Review says that those “embedded layers” visible in a PDF viewer are a result of having scanned a hardcopy and converting it to PDF: http://www.nationalreview.com/corner/265767/pdf-layers-obamas-birth-certificate-nathan-goulding