If you populate the Phone Number attributes in AD then the OC 2007 client will always display then regardless of what Access Level you set for contacts. Information populated in AD is considered 'public'.
If an AD attribute is populated then anything you enter int he Phones tab of the OC client will be ignored. The "Publish this Number" checkbox is also functionless at this point. AD attributes override anything typed into the Phones tab.
If the numbers are not normalized into E.164 format then the OC client will not display them, regardless of where they came from or what Access Level the contact has you set at.