This is actually the error message i get in Django. I'm running in Apache server located in Win NT.
[Error 5] Access is refused: u'Shared drive path'.
I believe the reason being apache services are running like a different user
I just read last evening when setting up the hMailServer (this is exactly what hMail been on their help, however it could apply here) it was better to run Apache web servers his or her own account, with appropriate permissions to complete that which was needed. This might not apply here, but it may be worth an attempt.