Currently Being ModeratedMar 14, 2013 8:34 AM (in response to omgitsme)
I'm presuming that if you cannot get your screen to lock then you also can't turn off the iPad as well? If so this is likely to be a hardware issue and you should contact Apple for assistance.
Currently Being ModeratedAug 4, 2013 9:30 PM (in response to omgitsme)
I'm experiencing the same issue. Found a solution: Go to settings > general > accessibility. Turn on assistive touch. A white dote will appear in the corner of your iPad screen. Tap the white button > device > lock screen.