I am almost 100% certain that this plugin sets wp3 blogs to PRIVATE. Of course, the results of this are disastrous, de-listed from Google within a week.
The problem appears to occur at random. For example, of four sites set up at once, one spontaneously set itself to private within a few days.
I have isolated and removed two completely non-essential sections of code responsible for this, and the plugin runs fine without them.
I also suspect that previous versions of this plugin were responsible for corrupted .htaccess files, as noted elsewhere in this forum. This is even more disastrous - the whole site becomes inaccessible. The current version seems to have had that "feature" stripped out, but there are still traces of it left.
It is otherwise an excellent plugin that does what it advertises.
The author is invited to contact me for details. I see no easy way to contact him. In the meantime, use this plugin at your own peril.