We provide pre-built Python bindings, so you should not have to build them yourself.
64bit Linux Python Wrapper:
http://www.pdftron.com/downloads/PDFNetWrappers/PDFNetWrappersLinux64.tar.gzIf you do need to build it for some reason, all the TRN_ConversionMonitorX functions are not officially part of the API yet, and may be removed or changed. I was not aware of any linking problems that this could cause.
It sounds like the PDFNetC.so that is being loaded for the interpreter is different then the one you use otherwise, so I would double check you are using the same so file everywhere.
Otherwise, I would simply comment out the references to TRN_ConversionMonitorX in Headers/C/TRN_Convert.h and Headers/Impl/Convert.inl, so you don't need them.