BuddyPress.org

Hi:
I am trying to use BP e-mail alerts so that collaboration users in a project know that some activity has taken place, but I am finding that some emails are not being generated, and then find that the topic, for that user, has been MUTED (ie shows FOLLOW rather than MUTE). Now I know that I have (and I am the tester) not clicked on MUTE, so how does it change from default All EMail to MUTE in some topic? Can’t see the gremlin at work, and can’t find some obscure rule that changes a Topic to Mute under some condition….
Using godaddy.com WP installation (newest) and the Add Plug-Ins of bbpress and BP, and the default BP widget theme….

Thanks
Ernie