Not sure which threads you're looking at because I know I usually state what the problem is and have never suggested folks to switch browsers. That is not an acceptable answer for a support question with the exception of Safari users trying to use the WYSIWYG editor. That issue has been documented as an issue with the browser and it's lack of support.
I do see two issues though.
1) It may be your browser. Last time I looked, I knew Microsoft put div tag support into their browser somewhere in the version 5 line. I know I can't see my own site with IE5.0 because of that issue. You may be hitting that.
2) Wideness. Usually the issue with the sidebar dropping is because something's too wide within the blog. I'm looking at this post for example. It is wider than the space set aside for the posts. Usually when IE hits something like that or a link that's too wide, it will force the sidebar down under the posts. For example, in this post, your sidebar is fine.
Hope this helps,