Commenting Not allowed, even in docs I create Reader 8.1.1

I cannot comment or bring up the comment menu in any document in Reader 8.1.
I do not know what happened. And this is true for at least 2 computers in my house. We have Acrobat 6 installed as a PDF Creator. But even in documents I create and have no security enabled, the Reader 8.1 tells me the document has "commenting" - "not allowed." I have tried everything I can think of, even un-installing reader and then installing a fresh copy, but the reader still does not allow me to make comments,

Any ideas?