Designing websites for all browsers can be a difficult task. We design sites to look good in 

IE6, IE7,  Firefox, Safari, Opera in a perfect world designing a site for all browsers would be great unfortunately with todays demands of creating web pages with funtionality and complex design unless you just had a page full of text with not much else going on you will run into problems. As you can see from the statistics below IE 5 is used only by 0.1 of internet users so small its not worth factoring this into modern web design. Here are 2008 browser statistics from the w3schools website

Already the new google chrome browser is up to 3% of users. Fortunately Google have put a decent amount of thought into their browser and it complies much like Firefox probably the best browser in my opinion.