Well you certainly have done a really tremendous job. I cant tell you how pleased I am to have been given the opportunity to help out. I cant see your problem which leads me to believe it is the IE peekaboo bug. A quick google will turn up the positioniseverything url. I do not know enough about your hnav to really see it.
If I could I really would encourage you to restore the text h1 header. It is vital to your search engine signature and to your accessibility. You can prolly reproduce it in text complete with drop shadows. It really is a must. There seems to be a lot more to read now. I might increase the line height a little and possibly hack the js quicktags to introduce one or two more heading levels. But all in all a heck of a job. Thanks.