Just upgrade to last version yesterday and, since then, I have problems with new comments in the activity stream: they do not appear or appear after someone else add an other comment.
Also some problem with the mail report: don't show the comments sometime.
This appears mainly with comments on photos (plugin bp-gallery) since it is the main activity of our site.
I've install BP 1.2.7 after I've upgrade.
Thanks
http://wordpress.org/extend/plugins/buddypress-group-email-subscription/