Re: Site Wide Activity stream not working
I’m almost certain that the problem has to do with items being tagged with timestamps from the future. The function bp_core_time_since() in bp-core.php returns the message [Use GMT Timezone] when the timestamp on an item is greater than the value returned by the core PHP function time().
The timestamp for blog comment and for blog entrie activity comes from the timestamp attached to those items in the databases corresponding to the individual blogs. That means that the timestamps on blog entries in at least some wp_x_posts and wp_x_comments blogs are incorrect by at least a few hours. I don’t know how this would happen. You can set timezones on a blog-by-blog basis, but I assume that WP ignores timezone settings when stamping new entries and looks only at GMT unix time.
I’m not sure what to recommend. Go into the database and look at the timestamps on some of those rogue comments and entries. Verify that they are indeed incorrect. If they are, then you’re looking at a WordPress problem. Try making sure that those blogs are set to the correct time zone (Dashboard > General, I think) and see if the problem persists.