Being a diehard Mac person myself (I have 5 Macs in my household), it works perfectly fine in Firefox for Mac OS X!! IE for OSX is a dead end product for the Mac platform (MS is no longer updating it), the sooner you retire it, the happier you'll be, trust me! I was an IE holdout, but once I got my hands on Firefox, I was kicking myself for staying with IE for so long. It is *that* much better, faster, and more stable! Safari is a close second for me.