Header doesn’t show in Explorer

I have my site up and running finally. I have everything pretty much like I want it.

The problem is that the header image I spent so much time creating isn’t showing up when the site is viewed in Internet Explorer. I can see it fine in both Safari and Firefox, though.

Any thoughts as to what a good solution would be?

Here’s my site address:

http://stitchinsheep.comberousse.com/blog

Any help would be much appreciated.