The "IE is a b*tch to develop for" thread

Ok, so here is where we'll discuss some problems for IE and what we can do to fix them.

When I was trying to get apps to launch under IE I found replacing this:

this.apps[app.id] = eval("(function() { /*...*/ })");

this.apps[app.id] = new Function("/*...*/");

Then I discovered that the theme system was not applying classes right. Replacing this: