**UPDATE** Click here for a possible fix from Jester **UPDATE**
This just came across the news wire from KingsIsle a few hours ago.
IE9 Compatibility Issue
There is a known compatibility issue with the most recent IE9 release candidate. If you download and install IE9, you will not be able to run Wizard101. Please know we will address this issue soon, but until then we do not recommend you install IE9 if you wish to play Wizard101.