First, all animation samples require a custom processor, so when you add a new mesh, you have to configure the correct mesh processor.
Second, a third option you can try (which does animation blending, animation composition, etc) is the KiloWatt Animation Library. It is, for sure, not geared towards only one model, and it also fixes some annoying problems with the SkinningSample (including the problem of generating really large animation files, the problem of not blending multiple animations, and the problem of being jerky when playing animations in slow motion).