The typedef for Mat_I_ULNG is incorrect in the nrtypes file. It currently reads
typedef const NRVec<unsigned long> Mat_I_ULNG;

and should be changed to
typedef const NRMat<unsigned long> Mat_I_ULNG;

This change is needed in the distributed files nrtypes_nr.h and nrtypes_lib.h.

This typedef is not actually used in any of the Recipes (or we would have found the error during testing), so there are no problems with the Recipes codes that derive from this error.