If you need to sync Powerpoint slides to a lengthy pre-recorded audio file in Presenter, the choice of format for the audio file is important. Save audio files intended for import into Presenter in mp3 format rather than WAV.

Presenter has a bug which shows up when using the Edit Audio window. WAV files will not play back beyond about 5 minutes into the timeline, making it impossible to sync slides to long WAV files using the Edit Audio window.