Installed font missing from WPF designer font family

Hi - I'm working in Visual Studio 2012 on a WPF application. We have 5 fonts we hope to use: 4 work fine, but one ("NeueHelveticaPro-49CmLight.ttf") doesn't appear as a selection for the font family in the designer.

I have the font installed on my system, and it seems to work fine if I use it in a Windows Forms application.

I didn't see any documentation describing any font restrictions for WPF: am I missing something?

Thanks!

Dave