Verify thatt he contacts icon is pointing to names.nsf by right clicking on it and selecting Application >>properties. Assuming htat it does poiint to names then verify that names.nsf is specified in the File>>Preferences>>Mail>> sending and receivbing area. IN any case the contacts properties and the file identified in the Preferences must match.
Check to make sure the old “names.nsf” is not stored in a different place. In other words, perhaps do a search and see if you have more than one “names.nsf” stored in different locations. Notes relies on that file during start-up, so it will need to pick it up from the start. It may be picking up a new “names.nsf” created by default when Notes 8 was installed, if the Notes 8 data folder is installed in a different location than the previous Notes version.
Also, once you get the contacts showing up correctly, check the Personal Address Book template and make sure it is using the correct one for Notes 8.