CSS and Microsoft's poor excuse for a browser
Tim Bray adds to the Microsoft IE is garbage chant that has been spreading around the Web developer community for some time. Oddly, until I think of Tantek, the IE browser on Mac is far more compliant. The font sizing issues that Tim discusses are largely only a problem on Windows version of IE browsers. Most other modern browsers (Mozilla (including its Netscape 6 and 7 variants), Opera, Safari, etc. all resize fonts even if the fonts are set in pixels.
In the accessibility community having a fixed pixel size has been taboo for some time. As I talk with more people with vision problems I find most do not use Windows IE browser to view sites, but choose one of the other modern browsers as they allow easy scaling of fonts (some like Opera even scale images). This seems to be a trait across the visually challenged users. Most users with visual difficulties have a strong dislike for the Microsoft browser just on this point alone. A few have mentioned they really like Mozilla browsers as they can easily change the skin on the browser to make the buttons and other elements more visible.
Me, I can read Tim's site just fine, which is ideal as Tim understands the problems and knows where the blame should reside.
Note: The MS IE browser on Windows shows its downfalls to those that are trying to us modern Web development techniques by using CSS layouts rather than table layouts for their work. As Web developers learn tableless layout is a pain to learn initially, largely because of IE 6 and lower do not follow the rules properly. To get Windows IE to render properly one has to hack the valid CSS to get the browser to render the page as does a browser that follows the standards. The irony is Microsoft claims to own the CSS patent.