my SV is trying to blow me up like a baloon

For the last two nights, I have managed to get my sinuses clear and keep my mouth shut, which is GOOD. Now my new Servo-vent keeps deciding after about an hour, to start blowing individual puffs, not very long, but harder and harder, even though my breathing is just fine. Once the blasts start puffing up my cheeks and making my eyes bulge, I have to turn it off and re-start the machine.

Any ideas? Could it be something I am doing with my breathing? Or is it something I could change in the settings.

Respironics BiPAP autoSV

thanx,

Talyn