Some mornings I awaken just enough to notice that I'm lightly snoring. I'm sleeping on my back when this occurs, which seems logical. I use a Respironics REMstar Auto A-Flex machine with humidifier set at 5 and a Breeze SleepGear nasal pillow mask and papcap chin strap. My mouth is not open at the t...

Have you tried the papcap? I tried other chinstraps before I discovered this one and this one works very well. http://www.pur-sleep.com/papcap-chinstrap. As you can see, the chin strap is separate from the cap which allows you to adjust the tension.