Have you tried closing all of the apps in the multitasking display and then reset the iPad? Sometimes closing everything and resetting the system can help fix odd issues.
In order to close apps, you have to drag the app up from the multitasking display. Double tap the home button and you will see apps lined up going left to right across the screen. Swipe to get to the app that you want to close and then swipe "up" on the app preview thumbnail to close it.
Reset the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple logo appears on the screen after which time you can release the buttons and let the iPad start up.