Only bp themes go into /wp-content/bp-themes. Normal wp themes do not go there. They live in /wp-content/themes as always. If you have just upgraded to 1.0 then the bp member theme directory name has changed from bp-member to bpmember due to changes in wpmu 2.7.1.
Go to the back end of wpmu BuddyPress > General Settings, make sure the default member theme is selected and press Save Settings. Should go away.