In the migration from Boost 1.55.0 to 1.59.0 I found a bug in Ublas. For instance, in 1.55.0 function OneElement() declared in boost/numeric/ublas/detail/concepts.hpp line 716 looks like this: template<> double OneElement (double) { return 1.; } However, in 1.59.0 I think there is a copy'n'paste typo, because the corresponding function (which has been refactored) looks like this: template<class T> T OneElement (T) { return T(0.0); } Please note that the latter version returns a *zero*, instead of a *one*. This same bug affects the vector overload of the function, but the matrix version looks correct (it returns identity_matrix). This looks like a copy'n'paste typo, from a similar function called ZeroElement(), that, of course, returns a zero. I'm not sure if there is time to get a fix for this in the 1.60 release... Regards!