I´ve come accross two groups of people when talking about Internet Explorer as a browser. There´s the usual "IE is shit, use Firefox" or "everyone has it so you know your web pages work". I tend to agree with both of these points and design and test using IE then run through it with Firefox on my Linux test box to make sure things are working OK.
The one thing that most experienced designers will agree on though is that IE is absolute arse when it come to CSS. A friend of mine had been looking at one of my sites and the next time I saw him in the pub he mentioned that he could hardly read it cos the font was so small. Another friend suggested he sit nearer to the monitor but I thought that I had better find out what was going on.
I tend to use pt or px for css measurements but the one that was being used on this site was using em all the way through. Em basically tells the browser to multiply the nearest exact font size in the style sheet by the em value. If there is no value set (if all the font sizes in this case were ems, as in this case) then it uses the default font size for the browser. For some reason on some systems this seems to break and default down to a really small font. Weird.
Gonna have to go through and put a definate font size in the body tag of all of my css files just to make sure.
I'm a web developer based in the East Midlands, UK and if I keep up the current rate, I might have developed 3 million sites by the time I retire