If you haven't done so yet, reboot your iPad. Press and hold Home and Power button simultaneously until the Apple logo appears. As soon as it's visible, let go of both buttons. Your device will power up on it's own.
If this doesn't help, restore your iPad using iTunes. Make sure there's a most recent backup to restore from (iCloud or iTunes). Connect your iPad to iTunes and restore it. This will install a fresh version of the latest software on your device, and should help getting rid of your issue.