When I try to publish a new master page in SharePoint Designer 2010, the publish options are missing.

Also, I can't do anything from the Master Page gallery within SharePoint as the needed options are greyed out:

Troubleshooting thus far:
In central Administration | SharePoint Designer Settings | All services are enabled
Site Actions | Site Settings | Site Collection Administration | SharePoint Designer Settings | All services are enabled
I am Site Collection Administrator
SharePoint Server Publishing and SharePoint Server Standard site features are active
In Library settings | Versioning settings, 'require content approval for submitted items' and 'create a version each time you edit an item' are both turned on
Any suggestions as to what else to check?
Thank you!