Instead of starting a new topic, I thought I would add to this one.
I have found today, that if you are in a menu category at the ticket screen, you can only scan products if the menu category Numerator Type is set to Big. This is also true for searching for a product, although not as big of an issue as scanning.
Maybe its just a case of having the barcode/search field at the bottom of all other menus instead of just with the Big Numerator set.