[C++-sig] properties in python class that extend c++ base

[Neal Becker]

I have a c++ class with a property:
class_<mod_t> ("mod"...
    .add_property ("SPS", &mod_t::SPS)

If I subclass this class in python:

class X (mod):

Then when python code attempts to access the property in the derived class,
it fails:
Boost.Python.ArgumentError: Python argument types in
    None.None(pi4_modulator)
did not match C++ signature:
    None(modulator<non_offset_modbase, double> {lvalue})

Is there a solution to this?