I am sure you can read it fine. But your question was if other persons had trouble with reading the text. And as you can see at the picture that I linked to the font is just way too small. (I tried other resolutions) I don’t think that Vista has anything to do with this, nor the use of Internet Explorer. I loaded your page in Windows XP with more or less the same result, and it made no difference using Firefox and Netscape. And when I watch your header.bmp (with the text) in a picture viewer (so without using a browser), the text is still too small.
(I meant of course that the “visible” picture doesn’t look centered. Good thing you are going to change that too.)