For every web developer / designer the issues in earlier versions of IE can be a real pain. Even simple styling such as margins and padding can make a design look like it’s upside down.
The obvious hacks for CSS involve using a separate style sheet and the old school <!– if IE–> but I always manage to avoid these mainly because I like to keep all the CSS in one file to keep overall page size down and it’s also more easier to fix other issues when all the CSS rules are in one file.
The easiest way to target issues in IE6 is to use the _property hack.
_margin:20px; /// this will only be used by IE 6
There is also a hack for IE7 which works in a similor way using the *
*margin:20px; /// this will only be used by IE 7
Although these may cause CSS problems to validators they are still very valid fixes and I have never seen a drawback to using these.