One of the challenging things about developing a web-based application is the number of browsers that are out there. Not only do we have to work with Internet Explorer, Firefox, Safari, Chrome, Opera and more we have to try and work with all the various versions of each one.
This is particularly an issue with the newest and the oldest browsers. For example, having made sure that we work with IE7, then Microsoft goes and brings out IE8 which is actually more standards compliant, but as such, breaks all the fixes people put in place to work with IE7. If you are using IE8 (I do) you may find that you need to use “Compatibility View”.