ok, this sounds strange. Can you check that the render file you are using (whether
core/default_libpd_render.cpp, or a custom one if you have it in your project) has the following lines:
//Add the current folder to the search path for externals
If this is ok, then it may be that your
YOUROBJECT_new method is returning
NULL, for whatever reason. Can you add a printf in
YOUROBJECT_new to make sure they are being called?