I'm not able to reproduce this here. I'm assuming this is happening only with the Relational View extension turned on, not just the Map to Relational View pieces.
Is there any way you could get me a callstack? This is likely in the AlternateViews\RelationalView\ShapeModel\ColumnElementListCompartment.cs file during a MeasureString call, but I don't know what is triggering your system to have a null font here. The fonts are retrieved from the DSL-managed class style set just like every other font in the system.
I'll be on the west side of the freeway this afternoon. I'd like to figure out what is doing this and get an 'a' drop out for 2013 if necessary.