Omnikey provided these instructions to remove the driver; it worked and I can now see the certificates on my smart card. I'm still having problems accessing CAC enabled web sites, such as MS Outlook Web Access, but Apple Genius recommending I reload OS X.
To uninstall the drivers please unplug the reader device first and then you only need to remove the
ifdokccid
macintel-2.6.3.bundle
folder from
/usr/libexec/SmartCardServices/drivers/
After deleting the drivers folder please reboot your computer and plug in the reader device again, then the free CCID driver, shipped with your operating system should be used.