Your older photos were edited with a previous version of Camera Raw which used an older process version. The new version of Camera Raw will respect and preserve those adjustments. If you want to change to the new process version go to the calibration tab in the adjustment panel and choose PV 2012. This could alter your image significantly depending on the adjustments you have made in the previous version. Sometimes those changes are unacceptable. That is one of the reasons why Camera Raw respects those earlier adjustments. This gives you the opportunity to choose which images you want to switch to the new process version.
Camera raw 7 (CS6) will display a small white square with an exclamation point when it opens a raw file that processed with an older camera raw process version. Click on this square to have camera raw use the new process version (PV2012) and the new menu sliders will be there.
You may want to retain the earlier settings and rendering by creating a snapshot before you convert to pv2012: Click the New Snapshot button at the bottom of the Snapshots Tab, type a snapshot name name in the New Snapshot dialog box and click OK. Create a second snapshot after converting to pv2012. You can go back and forth between the two to assess the changes from the newer process version.
Thanks for the quick response. I found the white square and am using it when I want to.