I've already found a lot of posts on this topic that are either unresolved or say "just don't use IE." As much as I stick to that rule for myself, I can't guarantee it for clients!
I'm using a theme called "Political Blog Blue 1" by 1800blogger. In IE only, the widgets in the right-hand sidebar shift below the posts content. It only happens on my main index page, not on any of the other static pages. It is not due to strange html formatting coming from pasting content from Word. The W3 validator finds eight errors but none of them have anything to do with the page structure.
There must be an answer... undying thanks!!