I am new to this site and just wanted to say that my daughter had a programmable medtronic valve for 2 yrs. From day one she had problems with it. On her foirst post-op visit the valve had reset itself. The surgeon did not believe that could happen.He thought he just wrote it down wrong. Several more times, shunt was found to be at wrong setting. He made excuses each time. Finally, when the shunt could no longer be set on anything but the highest or lowest setting, he replaced it with a fixed delta valve. My daughter endured 2 yrs of headaches, dizziness etc..because of this. We did contact medtronic about the problem. They said they were looking into it, but knew of no other problems. Really?