Here’s a snapshot of my HTML code as viewed after clicking View Source in IE9. I opens up in Notepad++

Here is the code as parsed by the IE9’s Developer Tool:

Why is there a disconnect between the two?
Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
As @Shadow Wizard suggested in a comment, the probable cause is some data character before the
<!DOCTYPE ...>declaration. For example, the problem is reproducible by taking a valid XHTML document and inserting the no-break space character (NBSP, U+00A0) at the very start of the document. But the presence of a BOM at the start does not cause the problem (at least not on IE 9, hardly on any browser in use). There is a large number of invisible or barely visible characters that might cause the problem.