I work for a uni as a web dev and IE8 is a real ball ache! A script I had developed that worked perfectly on my local version of IE8, was messing up on the uni build PC's also on IE8. I could not recreate the problem on my machine, like I saw you said in a comment (sorry not high enough lvl to reply there) then I noticed I was using 8.7.xxxx.xxxxx but the uni machines where running 8.6.xxxx.xxxxx ... the two versions seem to differ a lot ... I'm guessing this may be your problem recreating your erhhh problem, I know this messed me up! You can grab version 8.0 from Old Version. I'm guessing if it works in 8.0 it will work for 8.x.
In answer to your main question, you need to deal with it. IE8 still has a chunky share of the browser market, although IE8 doesn't have any possibility to grow, only shrink, we still need to cater for the users. Web development would be easier for a lot of people if we didn't have to deal with the messed up layouts and ignorance towards established web standards ... but at the end of the day, its competition, the devs on IE do a lot of cool stuff, I just wish they had a 6week update policy like chrome so they can fix the cool stuff that goes wrong!