You can set up separate rules for ie6 as Eric suggests but in many cases coding things appropriately will solve the problem anyway. We only resort to hacks when there is no other choice and when dealing with known bugs or behaviours.
Most of the browser differences can be put down to author error or perhaps an author not understanding exactly how things really work. Only once you have tried everything else then use a hack because maintenance is a nightmare once you start having multiple rules for different browsers.
If you have something that's not displaying correctly in IE then post the html/css or a link and we'll take a look and tell you whether it's a bug or a coding error.:)