How do I add a clearing DIV to the bottom of a region? In the eternal mission to care about Internet Explorer, I have a template region which needs a clearing &lt;div&lt;, since I think that ":after" and "overflow:hidden" tricks don't work so well in IE. (I'm currently not able to test this as I'm on a Mac without a virtual machine.)

Is there any region preprocess trick, or anything equally clean, in order of adding a clearing &lt;div&gt;? I'd prefer not to use Javascript, or add an entire block for this purpose, if it is possible.
I would find a common class for your region(s), and add in the clearfix rules.  With kosher HTML and CSS, I don't recall the last time this didn't work in IE for me.