Hi all. I've now been on CPAP for 1 week. So far so good. I can't say I feel better yet, but I know I don't feel worse. My only problem is falling asleep. Once asleep, I'm good to go for the most part. Lat night I did encounter a problem. When I turned my machine on, the noise from the air flow inside the machine was very loud every time I inhaled. Needless to say I turned it off for the night. Today I called the ME I purchased the machine from and they asked me to bring it in. They inspected the unit and couldn't find the problem either. We then tried replacing the tank for the humidifier. When we took the old one out, I noticed the rubber seal around one of the air flow passage ways was not properly seated. We fixed it, and viola....no more leak or noise. I felt like a total fool since I must have moved the seal yesterday during cleaning. The tech said they never saw that before either, which made me feel better. My machine is the Remstar M series A flex, which some in here said was a great machine. Even though that is the only machine I know, I would have to agree.