I'm having troubles uploading photos, but there is definately a bolt holding the crossbar to the "foot".
It's sort of a T-nut arrangement, with the T residing in the channel on the bottom of the crossbar (this channel has a rubber strip sealing it). If you remove the rack, you will clearly see this bolt (it's an 8mm oval head bolt IIRC).
Loosen this bolt to adjust the feet in or out.
Since this bolt is oriented "head down" when on the vehicle, it's possible that Manhattan potholes have caused your bolt to drop out. In this case, you'll hear the "T" sliding around inside your crossbar (unless it fell out somehow).