Tonight, I checked my blog site with Internet Explorer 6, from an older computer that I had to keep on that version due to some software that was not compatible with IE7. I was shocked, that the style for my blog was not rendering correctly there. My usual blogging is done via IE7 from a laptop. I did check that the fire Firefox rendering was good (but it autoupdates to the most recent version). I then check the web stats on Web browser usage and found that about 1/2 of the people use IE - and IE6 is half of those. If you find the CSS Selector at the bottom, the page may render better with another style.
It was intersting to note that Firefox was approaching 50% of the market for browsing - I saw a post from Tim O'Reilley (of O'Reilly books) that over 1/2 of the users were on Firefox at his site.
If you can switch your browser to something higher than IE6 - your experience will be better - and right now Firefox is better on CSS rendering than IE6 or 7. I will be changing one of my computers to see the impacts of IE8 in the very near future.
I will have to take a look with the computer with Safari's browser and then try Googles new Chrome Browser too. Certainly there is competition here for Microsoft in the browser market.
One other note - in editing this post, I did it in Firefox, and the positioning is different from what I am used to in IE7, which required some scrolling out to the right to see the post entry text in its entireity.
The differences in browsers give an impression of instability, and the idea of doing business apps entirely in a browser setting is going to need something to bring them into a more cohesive user experience.