I am trying to get my subscriptions to be non-exclusive so my members can choose more than one at a time because we offer multiple subscriptions. I have made all plans non-exclusive but when i try to upgrade from a free account to one or multiple plans i get the following error message:

Chosen plans combination is not allowed (you must choose coherent plans selection, e.g. mandatory subscription(s) must be active or mandatory plan(s) must be chosen).
Please press back button and select the subscription plan to which you would like to upgrade.

I am using the following for each plan:
parent plan: top
exclusive plan: not exclusive, other plans of same parent can be subscribed same time & subscription is not mandatory
hide children: no children plans always visible if any


I would like to be able to offer my members the ability to select more than one at a time. im using the following
joomla2.5
CB 1.9
CBsubs 2.02 (will be upgrading to 3.0)