Supporter Plugin Settings Page redirects to home page

I've installed the supporter plugin. I can see the tables in phpadmin and get a menu in the Super Admin field - Supporter (). I can go to into this menu but when I click on Settings it redirects to the front end home page of my mainsite.

I installed it from the premium plugins page using the cPanel file manager, otherwise I don't think I've done anything unusual. I've also added the supporter-quota.php file into mu-plugins.

On wp3.0, new install through wp.mu.

Does anyone have any pointers? Thx - Bruce