Intellipoint software on OS X Mavericks not recognizing Intellimouse
I resolved this by uninstalling the Intellipoint Software (using the provided uninstaller) , rebooting (as requested by the uninstaller), reinstalling, and rebooting (as requested by the installer).  I suspect something went wrong in my prior in-place upgrade of the Intellipoint Software.  I did lose my Intellipoint settings, but I had made note of them prior to uninstalling.