Hello
Being new to this forum, I did not previously reply (not a nice comment about"she did not respond, since I am a "he" and am very computer illiterate.
However, the issue was with a brand new Ipad2 that I received as a gift.. The ringer icon kept appearing in the middle of my screen, then disappear, then reappear. At this point I didn't even realize there was a ringer button on the side of the Ipad2. Finally I contacted Apple Support, they requested the Ipad2 be returned to them for repair. Please note, this is on my initial setup ... I hadn't even used the Ipad2 for anything. The result was that the Ipad2 was defective, and Apple sent me a brand new one. Since then I have not had any problems.
Good luck