Hi Robert,
Can you check your Preloader settings for your Project (Edit--Preferences -- Start and End, set it to 100 (if not already).
Do you have audio on first slide itself, if yes, can you movie the audio from the time line to around .2 or .3 sec ahead and then publish it again and check it on the LMS.
Also, let us know what is the value of Audio Bitrate from SWF Size and Quality.
Thanks,
Anjaneai