BuddyPress.org

The fix didn’t make it into 1.0.2, but is in the trunk:

bp-xprofile-signup.php line 261 change:

$bp_blog_signup_meta = array_merge( $bp_meta, $blog_meta );

to

$bp_blog_signup_meta = array_merge( (array)$bp_meta, (array)$blog_meta );