Problem executing .py file

hello people,
i have successfully installed the RDS blocks in the gnuradio and when i
try
to execute any .py file which contains the RDS blocks, it is showing me
the
following error

Traceback (most recent call last):
File “crc_fm_rds_tx.py”, line 12, in
from gnuradio import gr, rds
File “/usr/lib/python2.6/dist-packages/gnuradio/rds.py”, line 7, in

import _rds
ImportError: dynamic module does not define init function (init_rds)

will be very thankful for the solution
regards