The sleep/wake button doesn't work. It presses in so it isn't stuck but it doesn't shut the iPad down.

Try reset iPad

Hold down the Sleep/Wake button and the Home button at the same time for at least ten seconds, until the Apple logo appears

Note: Data will not be affected.

Try restore iPad

http://support.apple.com/kb/ht1414

Note: Data will be lost.

I have the same issue. The magnets in the Logitec cover I am using are the cause of the problem. If I take the unit out of the case or rotate it 90° in the case, it works.