This is truly fascinating. I worked on another problem and somehow solved this one. I say somehow because I did change the CSS around a bit and I can't really say what change that solved it, although it is probably the removal of the background image in the BODY. Here's the story.

The website menu will be JavaScript driven and when you click the appripriate link the old DIV will slide out and the new DIV will slide in to replace it. In order for this to work, the other DIV was placed outside of the screen. Since the BODY had "overflow: hidden", no scrollbars were visible and my right-aligned background showed up in the upper right corner. With the exception, naturally, of IE (6 and 7, didn't try 5.x) where it didn't seem to show up at all. Setting overflow to "auto" revealed the background way out by the hidden DIV where it probably sat all along in IE.

I guess I could have pinned the image down with "fixed", but I needed to rework some of the XHTML anyway so I removed the image from the BODY and added it to my header DIV instead and placed it where I wanted it. When I looked at the result in varous browsers, the Safari problem was gone.

Curious and annoying.