During weekend we went ahead and fixed all notices and warnings in all our plugins, components and modules for VM. We only have one left and we think this one is actually Virtuemart that is giving it.
Undefined property: TableVmusers::$shopper_groups in E:\wamp\www\virtuemart_generic\administrator\components\com_virtuemart\models\user.php on line 163
I understand its problably no problem. Just that I like the idea of having a not so low level of error reporting in Joomla setting to see whats going on.