[Discuss-gnuradio] import error in multimode.py

[md123]

hello all.  i  am trying to run multimode.py in the GRC. GRC shows the import 
error in its flow graph error viewer:

Error 0:
Block - import_0_0_0 - Import(import):
  Param - Import(import):
    Import "import multimode_helper as mh" failed.

The directory /home/matt/bin contains "multimode_helper.py" and this file path 
is in the PYTHONPATH.  since i know the correct file path is in PYTHONPATH and 
i am still getting the import error i am really confused here.

Thanks for any help. 

Matt