Dunno where you got that idea... I'd suggest whatever it was you ignore it.
Given it's opposing alignments, and the lack of predictable behavior for table-cell and sizings... uhm... no...
I'm stuck wondering why it isn't working for you.... float left, float right, no float. Should go right in no problems. Do you have an example/live page of it so we can see it failing? I suspect whatever is going wrong is probably
Though... did you forget to add float:wrapping like overflow to the outer wrapper? Are you just asking why the parent #footer is only showing 0px tall with it's borders stacked behind the floats? If so, that's a lack of float clearing/wrapping. Add overflow:hidden to #footer, be done with it.
Though I would suggest losing all the pointless fictional "runat" nonsense, but that's just ASP taking a whiz all over your markup. I'm also curious why you've got H3 there when none of them have content after them... since numbered headings are to indicate the start of a subsection, not just text you happen to want larger on a page.