I can't run it at the moment but I'm sure there is an option at the end of the wizard to run another scan instead of exiting. I seem to remember that it took me a few tries before I spotted it because I was a bit "trigger happy" with the left mouse button and was finishing the wizard without checking the options.
Like I said, I can't run it just now so, if I'm completely wrong, I have to apologise - I must be thinking of a different scanning application that had the same iritating problem!