Embarrassing moments ...
I have been able to reproduce this problem and the only solution, thus far is marking the Product as Virtual when there are both Attributes with an Option Name group with Downloads and Attributes with an Option Name group without Downloads on it ...
I am not sure why I could not trigger this issue on my initial testing, other than maybe I forgot to select an Attribute from the Option Name group without a Download on it ...
This does indicate that to use the Product marked as Virtual, with the Option Name group without a Download that there has to be a selection made ... meaning, there has to be a forced Option Value from the Option Name group without the Download in order for it to handle a Product with a Download option name group and an Option Name group without a Download and the Product itself being marked as Virtual ...
Sorry for the confusion on this one ...
