Problems linking native library with Xamarin.iOS 7.2.1.42

I updated to Xamarin.iOS 7.2.1.42 today and I am now getting lots of MT5210 (Native linking failed, undefined symbol) errors with my native C++ library. I have read the notes here and have tried to use the legacy registrar settings, but without any luck...

Here are my additional mtouch arguments (for Simulator) that worked before updating to 7.2.1.42:

-cxx -gcc_flags "-L${SolutionDir}/${ProjectDir}/libs/ -lmylibrary -force_load ${SolutionDir}/${ProjectDir}/libs/libmylibrary.a" --registrar:dynamic

And I've tried changing them to:

-cxx -gcc_flags "-L${SolutionDir}/${ProjectDir}/libs/ -lmylibrary -force_load ${SolutionDir}/${ProjectDir}/libs/libmylibrary.a" --registrar:olddynamic

and

-cxx -gcc_flags "-L${SolutionDir}/${ProjectDir}/libs/ -lmylibrary -force_load ${SolutionDir}/${ProjectDir}/libs/libmylibrary.a" --registrar:legacy

without any luck.

Additionally, I've tried wrapping this library in a binding project and I get the same errors.

Any ideas?