Hi again,
Okay I have looked into this further and been able to find the cause of the issue, so I’ve just created and submitted an update to the App which is currently being reviewed by Microsoft.
In the next few days (Est around the 16th April 2015) please check if your ‘Site Contents’ to see the update when it is available, the update link will look like the following:
If you are not an administrator you may need to speak to your administrator to install the update.
Please let me know if you continue to have any problems after installing this update.
Martin