Much better - the issue before was that the forum text was scrolling on top of the header, and I assume it's supposed to be scrolling under it. But now it's not scrolling at all, so no problem. (Maybe you just disabled the scolling for IE? If so, that's a perfectly acceptable solution.)
My next suggestion is to make the header about 1/4 the size it currently is. The header fills almost half my browser window on my laptop, leaving not much room to read the actual forum. The big buttons make sense on the front page, which is largely graphical, but not so much in the forum which is textual. A scaled-down header, ideally with just the text of the buttons and not the icons, and a correspondingly small DIF logo (or just :Home: in the same text as the other buttons) would make the thing much less obtrusive.