Never used the airplane mode--never had this happen--had mine about the same length of time. You might as at the Apple site..I have the site saved 'somewhere' --(too many laptops to turn on right now). But start with a question to
http://forums.techguy.org/ I call this my computer bible. They might be able to answer for you. Otherwise, Apple has a site that you can search all kinds of info re the iPad.