Can't Create Assembly View Orientation

Hi,

Having a bit of a random issue with view orientations in assemblies. 

I'm trying to create a new view for a detailed drawing however when I go to create a new view (space bar, click new view etc) this won't save in my list of views!!  However if I open a part from the assembly and repeat the process it will save the view orientation no problem!

Am i missing something in my assembly settings or is this a bug!?  I've never seen this before and using this process for other drawings we've done here has been fine.

Any help appreciated as always.

Thanks

Dave

SolidworksAssemblies