Weird (even weirder is that I keep saying that today)
If you haven't restarted you iPad recently, you should try that.
Hold down the power button until the power slider appears. Slide it off. When the iPad finishes shutting down press the power button again until the Apple logo appears.
Check things out.
If that did not work try a soft reset. Hold down both the power and home buttons until the Apple logo appears. Ignore the power slider if it shows up. The iPad will reboot. This will take a bit longer than a normal start.
Check it out.
If that does not fix it you may want to call Apple Support. They will probably walk you through a restore, which I could do, but if it didn't work you'd probably still have to call Apple, and they would still walk you through a restore. This way you'll be one step closer to getting a new ipad if it turns out to be a hardware problem.