BuddyPress.org

WP 3.5, BP 1.6.2, Default BP theme

This is a brand new install to .com/bp/

All attempts to ‘post update’ for members or groups activity result in this message.

“There was a problem posting your update, please try again.”

It’s not the issue in /ticket/4523

wp_debug shows this:
Notice: Undefined index: item_id in … /wp-content/plugins/buddypress/bp-themes/bp-default/_inc/ajax.php on line 274

Any suggestions ?
Everything else is working as expected.