Audio issues

Hi,

i seem to be having some serious audio issues, which are similar to others on here, but i have yet to find a sloution after reading through the suggested support options.

I record narration for a new presentation in presenter 13.  I then used the audio editor to make some improvements, including recording new sections of audio in some slides to replace bad bits.  However, once i published the presentation i found that a number of slides that i had edited were starting the audio from a point midway through the narration.  The narration would finish, but the sldie would continue to play in slience for the remaining time.

Since then, i have tried repeatedly to use the record narration function to overwrite the audio on these files, however, after exiting the narrator and then previwing or publishing the slides, the new narration is not there and the original old audio, starting from mid narration is still there.  I've removed old ppta files, i've saved to a C drive, the relevant add-ins are enabled, but the issue remains. 

Regards

Jonathon