I just noticed that in the dokuwiki.php file there was this:
/* Notification Settings */
$conf['subscribers'] = 0; //enable change notice subscription support
This parameter = 0 no matter what I do with the 'Allow users to subscribe' setting in the configuration pages! I'm not sure how this can be, since the file is read/writable.
So I manually changed it to be:
$conf['subscribers'] = 1;
However this made no difference.
Any advice would be great.
Andrew
===== EDIT =====
I just discovered that it is actually local.php that gets changed by configuration manager, and this is happening successfully. So the above notes are irrelevant now.