Using British National Grid projection in Mobile Viewer

Hi,

I'm using Infrastructure Map Server 2014.

I can use the Mobile Viewer to view maps provided that the data is in a lat / long projection.

If I create a map based on data that is in the British National Grid projection the map does not display properly. When zoomed in no data is visible. When zoomed out a long way the data is visible in a tiny section of the centre of the screen. All of the layers are set to display over the full scale range from 0 to infinity.

Has anyone else used the Mobile Viewer with the British National Grid projection? Does anyone know what I am doing wrong?