OK, found a solution. I modified the content_top.png and included my banner on top of it. I then disabled the banner display in header.php (just comment top_header_image(); on line 33). Finally, I edited the CSS : I set the content_top image height (line 42), and adjusted the positions of the pages menu, the search menu and the RSS feed menu (just adjust the “top” settings on line 64, line 43 and line 40).
Works fine for me ;o)
Result is visible on my blog (no content yet, and in french, but who cares).
Bumping, got the same problem here. I’ve tried to modify the #top and .header_image heights in the CSS but all I’ve managed to do is to mess up the whole blog.
Any ideas ?