Trying to edit Access Rules for BM 3.9
Edit what it allows me (see my message above), click apply then close then

Reopen browser, relogin & I get:

Note: This configuration is currently being edited by cnxxxxxxxxxxxx
(10.x.x.x) since 02/01/08 14:09:58. Click unlock to override.

That is madness!
To me it seems that BM 3.9 is simply not a usable product in the current