Re: Sitewide Activity Widget
First of all, with the version of BuddyPress trunk that you have installed, you will now only have one activity table in your MySQL database. This table is wp_bp_activity_user_activity_cached.
I know that based on the private message you sent me, you have read this thread which details why this is the case. So, unless you added those tables back to the DB, I am surprised that you even have the other two activity tables in your DB. If the BP upgrade was successful, it should have automatically removed those two tables.
Trying to add those tables and their corresponding data back to the DB will do nothing. The BuddyPress codebase no longer references those other activity tables. They are no longer needed.
As for the Site Wide Activity widget, make sure that you log into WPMU’s backend and go to “Appearances > Widgets” and remove the Site Wide Activity widget and then add it back. Also, your widget will not show any activity until someone does something that gets recorded into the wp_bp_activity_user_activity_cached table.