Enabling RRTI?

I'm using AtmelStudio6 with the VisualMicro plug-in, on a Due project. when I try to use RTTI, I get this error:

MSMStateMachine.cpp:19:40: error: 'dynamic_cast' not permitted with -fno-rtti

How do I disable the no-rtti option in the build? Why is it even set as the default?

Regards,
Ray L.