BuddyPress.org

Short answer: theme error is complicated. I’m writing up a Trac ticket and will put the link here later.

Workaround: duplicate your /bp-member/* folders into /wp-content/themes/. This will populate the correct info in the drop-down box. Once this issue is fixed, you can remove the duplicates from /wp-content/themes/.

FYI, you can also trick this with a link.

from /wp-content/themes:

$ ln -s ../bp-themes/THEMENAME THEMENAME

Worked great When you’re done, delete the link.