Internet Explorer was probably created because Microsoft hates developers, and here is yet another problem to prove it. IE6 and IE7 (thankfully not IE8) have problems when it comes to rendering overlapping absolutely positioned elements. Learn how to fix the bug that causes overlapping with absolutely positioned elements and z-indexes.
When browsing the web there are four kinds of sites: Sites designed bad and hard to use, sites designed bad and easy to use, sites designed good and hard to use, and sites designed good and are easy to use. Don’t fall into the trap of having a great looking site that doesn’t pass a usability test and turns away your visitors.