IE z-index Bug
Again, stupid IE bug made me spent another hour or two to workaround this css bug. The problem is IE seems to have independent z-index stack for a relatively positioned elements. Visit here using IE and FF, to see what the problem is. I am using Safari in my Mac to develop a website, and I don’t really have any problem with FF, but I usually spend two-three hours to fix stupid css mis-behavior in IE. (sigh)
Anyway, to workaround this problem, every relatively positioned elements should have defined z-index. And here are other resources that I’ve used to find it.