I just sent you an email too.. think we're getting ourselves crossed between here and email. I apologized in the email, and will do it here in public as well. When I called out the errors above, it wasn't meant to be harsh. Our notifciation of a mis-ordering of the user plugins is terrible (there's a red 'x' to the right of the plugin even though there's a green check to the left (indicating it's published). For the error in red, we say 'recommend' you do something, when it's actually required.
Anyways.. Joomla 1.5.8 is too old. I can't remember what release, but it was between 1.5.9 and 1.5.11, Joomla changed some minor things internally that we (and many other) extensions use by default. Upgrading to anything past 1.5.15 should help, but yes, 1.5.20 (most recent as of a few days ago) is highly recommended.
Please let us know any other issues you're running into. I'm sort of confused as to the 'current' problems. Would love to get you set up and happy with your subscription and our support.
Thanks!