Result module "Not allowing to select more than one quiz at the time"

I need to select multiple quizzes for the results page.
When I go to select quizzes it allows me to select only one.
It happens on both modules vQuiz Results and vQuiz Myresults
I've attached the screen shot of what I see in the back end.
I think there might be a missing button on the selector or something.

Any Ideas?

Thank you