Hello Chris,
Thank you for your cooperation. I checked code, but I did not found any problem. I'm sorry but I do not think your problem is in M-Turbo. It looks like that problem is somewhere in the Magento settings. Eventually, problem may caused also by a 3rd party component that change the behaviour of Magento.
The solution of this problem is beyond the standard customer support. If you want to so that we will looking more deeply at this issue then you can buy paid support. In this case contact
Diese E-Mail-Adresse ist gegen Spambots geschützt! Du musst JavaScript aktivieren, damit Du sie sehen kannst.
, please.