So it would seem that there is a new 3px gap bug for IE7. I think it may be related to the original 3px bug that was prevalent in IE6. However according to Position is Everything (A very well respected source of great IE trickery and design principles), this bug died with IE6 (If only IE6 would actually die).
So, while working on getting a few <div>s to ride up the side of a floating <div>, I found that IE7 does still have some sort of problem that causes a 3px gap to develop beside the "floater."