glorcal,
Keep clicking on the X to stop Genius. I don't know why it is grayed out in the menu, it is there on my PC.
If you are PC-savvy, please send a crash report to Apple. The directions are in RoyB's post here
http://discussions.apple.com/message.jspa?messageID=9143156#9143156
There is also a very good idea from another user, RCElliott,
in that thread. Disable your internet connection, start itunes. It will not be able to connect to the store due to no internet, and you can turn Genius off.