I wouldn't have a problem with IE if they were at least consistent about the bugs. The biggest problem is they introduce new problems in each release. I learnt how to deal with the box model issues in IE6 then they released version 7 where they had some new, even more blatantly stupid mistakes

IMO microsoft should drop the IE project all together and adopt the mozilla engine or buy the webkit license (or even better use Opera as the default browser in windows [man can only dream])