I am not sure what has happened but I am using the Chunk Theme and the side bar will not stay in the correct place. It moves over into my content area. I also noticed when I have looked at using other themes not all of them are displaying correctly. For example, if I use the Vintage Camera theme the date shows up as in a square not a circle.
I am not sure if this will help you @metonymic… but I noticed that when I have the “compatibility view” button on in IE is when I was having the troubles. Now that I don’t have that one it seems to work fine! Hope that helps.