To be honest, if I were designing a website I wouldn't make a header that large because of people with 1,024x768 resolutions. When you design, you MUST design with 1,024x768 in mind. Of course, I don't care. I never look at GOF on any less than a 22" monitor. Looks great from there.
The only suggestion I could make would be to replace the top boarder around the portal and search section with a separate div and shrink those leaves down to make sort of a leaf border. BTW, here's a screenshot of what GOF looks like on a 1,024x768 resolution:

I should point out that this is the ENTIRE screen. It might be acceptable if you reduced the size of the bottom leaves by about 30px horizontally and if you got rid of those.......things on the side of the banner. Also, the abrupt end of the leaves is very apparent. I suggest fading them out like with the banner. You can do so quite easily by using Photoshop or Gimp (free Photoshop alternative).
Sorry but I've become MUCH more of a web design critic in recent years. I'm even finding faults with the things on GOF which I have made including the reply buttons, banner, and background. GOF already has an enormous header. Adding more to it just doesn't comply with web design standards. What else can we do? I'm not exactly sure. Perhaps a background/buttons change would be better.