Can't use components in FlexMobile Project

I am trying to use flexlib in an Flex-4.5-Mobile-Project. But it won't compile.

While compiling I am always told, that

"'ScheduleViewer' declaration must be contained within the tag, since it is not assignable to the default property's type 'Array' or element type 'mx.core.IVisualElement'."

Could there be a simple solution for this? As far as I can see, should Schedule Viewer extend UIComponent which extends/implements IVisiualElement.

It would be great to be able to use flexlib in the "new Projects".