About jQuery slideUp, slideToggle flicker problem in IE

quite busy at work recently, when nothing to see jQuery his fiddle fiddle. Animation features in play when the slide × × accidentally discovered the effect in ie there are some problems. Every time when the operation will find slideUp elements disappeared after the last gasps, the flash so it over and then disappear. Studies have not resolved a long time, then ask my students, he soon found the answer to help me.
The easiest way is to add a line doctype, , declared the standard of W3C standards and found everything running normal.
Also if you know the root cause of this problem, we can not add this in the case of replication W3C standard jQuery code to solve this problem. If you are interested, you can see http://aqr199.myweb.hinet.net/jquery_slide_iebug.htm explained here is still pretty clear. Of course the good thing do not know why it is inexplicable on the outside wall, and also need to see the original wall Oh.