Thank you for the validator link. That helped some. I cleared up all but one (minor formatting) error and it came back and said I had an extra </div> tag at the end.
Since I know the count of div tags in the file was right, it occurred to me that maybe one open div tag was commented out. Indeed that was the case! As soon as I commented out it’s companion end div, the problem cleared up.
Thank you!
I just fixed two different themes where text wasn’t wrapping around images nicely.
The solution for me was to add code to the .css sheet so that the native alignleft and alignright img classes worked properly.
Here is the info I used to fix my problem…
http://codex.wordpress.org/Wrapping_Text_Around_Images
I think you need to move the breadcrumb code into a lower / more detailed <div> section of the single post page.
My breadcrumb was always giving the first post title in the category when I had the breadcrumb code in the content div. When I moved it down to the top of the post div, the problem went away.