RMB post form now appears even if the RMB is empty

So I was messing around, and it turns out that if there aren't any RMB posts, the .rmbrow:first class doesn't exist.  As far as I can tell (I've tested on both empty and full RMBs) if you replace it with .widebox:first everything should work, as there isn't anything significant between the first .widebox div and the first .rmbrow div.