auto vs c-flex vs bi-level????

What alternatives are there to the standard constant pressure machines like the remstar plus? I've had trouble getting comfortable (felt like I couldn't breathe) even at low pressures although the ramp function is leaps and bounds better than the first loner machine I was given. Also, are there effective contraptions for keeping your mouth closed? I'm sure I read about someone using tape! I can't believe I'm asking this but....what kind? I switched from a nose mask to a full face mask with no appreciable change in leakage.

Regarding taping the lips closed to stop air leaking from the mouth, this is from a post by someone else on another message board:

I tape my lips shut with 1" wide 3M Waterproof tape (flesh colored). I then cover my taped lips and mouth with 2" wide 3M Durapore Cloth Tape (white). The waterproof tape keeps moisture off the cloth tape, so it can do it's job and keep the mouth closed. I turn down a lower corner of the Durapore tape for easy and fast removal. I've been doing this every night for almost two years. Works every night for me. Wouldn't go to bed without it!

I've seen other posters report using these things: Nexcare Active strips, Nexcare Ease-Off, micropore tape, regular adhesive tape...and yes...even duct tape in desperation.

Chin-up strips (not to be confused with "chin straps" which are mostly useless, since air can still puff out from between closed lips) work for some people. You might want to try "Chin Up"'s before going for tape. If the machine pressure is fairly low, just keeping the lower lip "up" more can accomplish a pretty good mouth seal.