Can't stop audio when naviagting between ToolBook Files

PowerPac v. 12.128
I am using pgSoundLoader (with showControls set to an rgb value and stopOnPageNav set to true) to play mp3 files. A field named "Player" is on each page and it calls pgSoundLoader when each new page loads. Each lesson is created in its own ToolBook file. Each page in each lesson plays only a single audio file and audio for each page is unique.
All works well within each lesson; when navigating to a new page the old page's audio stops and the new page's audio starts. However when navigating to another lesson file, two audio files play. On click, the navigation button to the next lesson calls pgSoundLoader with action "unload" and then calls to Go to page to go to the next lesson. The audio from the current lesson stops and the next lesson window pops up (as expected) but then audio from both the old lesson page and the new lesson page begins to play simultaneously.
I tried using a differently named player in the next lesson (Player2) but the results were the same.
Any ideas on how I can get audio from the previous toolbook file to stop when navigating to a new toolbook file?
Thanks,
Gene
I am using pgSoundLoader (with showControls set to an rgb value and stopOnPageNav set to true) to play mp3 files. A field named "Player" is on each page and it calls pgSoundLoader when each new page loads. Each lesson is created in its own ToolBook file. Each page in each lesson plays only a single audio file and audio for each page is unique.
All works well within each lesson; when navigating to a new page the old page's audio stops and the new page's audio starts. However when navigating to another lesson file, two audio files play. On click, the navigation button to the next lesson calls pgSoundLoader with action "unload" and then calls to Go to page to go to the next lesson. The audio from the current lesson stops and the next lesson window pops up (as expected) but then audio from both the old lesson page and the new lesson page begins to play simultaneously.
I tried using a differently named player in the next lesson (Player2) but the results were the same.
Any ideas on how I can get audio from the previous toolbook file to stop when navigating to a new toolbook file?
Thanks,
Gene