[mod_python] cannot import name psp

When I do

    from mod_python import apache
    from mod_python import psp

I get an error, but when I do

    from mod_python import apache, psp

I don't get an error.
But I still get this error every now and then -

Mod_python error: "PythonHandler mod_python.publisher"

Traceback (most recent call last):

File "/usr/local/lib/python2.2/site-packages/mod_python/apache.py", line 299, in HandlerDispatch
  result = object(req)

File "/usr/local/lib/python2.2/site-packages/mod_python/publisher.py", line 136, in handler
  result = util.apply_fs_data(object, req.form, req=req)

File "/usr/local/lib/python2.2/site-packages/mod_python/util.py", line 361, in apply_fs_data
 return object(**args)

File "/usr/home/krishna/work/head/ironport/qa/autoweb/lib/myprogram.py", line 36, in form_reply
 from mod_python import psp

ImportError: cannot import name psp


Why is this occuring only now and then ?
That too this is happening only for importing psp module.

Thanks,
Krishna.