>did you try the access via
document.getElementsByTagName("body")[0].innerHTML
or
document.getElementById("someID").innerHTML
(after assigning an ID to the body tag)?
Well, believe it or not but the logic was like this:
ASP page containing javascript was including a javascript function that was calling another javascript function (to get the innerHTML) where this function was made accessible by including a reference to an external javascript file. I just remove that external reference and plugged the function directly in the ASP page and it started to work as expected. Really weird!