No able to play back and download voicemail recording

I have a problem playing back the voicemail recording in the voice mail montior gui. I am using FreePBX v2.8.1.4 with asterisk v1.8.5.0. When I click on the play button in the vice mail montior gui, nothing show up and when i click on the download button, it show the 404 file not found error message. I am using the internet explorer 8 to run the playback.

the voicemail recording is listed in the voice mail monitor gui and these files are also showing in the /var/spool/asterisk/voicemail/default/1000/inbox

could some one tell me what could be the possible cause for this problem?