I've just been looking at reading the CSS 'caption-side' property for a caption in my tables, but I was getting an empty string. On a bit of experimentation I discovered that this is occurring because I had removed the element from the document (to clarify if the node is left in the document it works as expected).
I've put together a jsfiddle example here: http://jsfiddle.net/UqY8X/ .
I must confess I can't imagine that this will be a particularly high priority issue! Or indeed it might even be won't fix, but I thought I'd report it anyway, as it wasn't what I was expecting to happen.
*** This bug has been marked as a duplicate of bug 14563 ***