Have you tried a 'soft reset'? With all phones and tablets these days, you need to reset them once a week at least like you would with a computer.
This is not a simple shut down and restart. It's also known as a 'forced-shutdown'. To do this you need to pull the battery out without turning it off, leave for 30 seconds and then power up again.
Obviously you can't do that with Apple products as you need to take it apart to remove the battery.
So with an 'i-device' you need to do a 'soft reset'.
To do this you hold down both the home button (the round button in the centre at the bottom) and the power button at the top corner.
Keep these held down all the way through the 'slide to shutdown' screen. Ignore this and keep the buttons pressed. After a few seconds, the device will shutdown. Leave it for 10 seconds or so and then power up as normal.
***This does not delete anything - it's just a more definite way of restarting you device***
This works for all versions of the iPad and iPhone.
Hope this helps.
