Q: My I pad would not rotate yesterday, then it started up. Ok this am and by afternoon it quit rotating again.

Is the rotation switch enabled?

is there a lock to the left of your battery, http://support.apple.com/kb/TS3805, this should help you out with that.

The Apple Support Communities are an international user to user technical support forum. As a man from Mexico, Spanish is my native tongue. I do not speak English very well, however, I do write in English with the aid of the Mac OS X spelling and grammar checks. I also live in a culture perhaps very very different from your own. When offering advice in the ASC, my comments are not meant to be anything more than helpful and certainly not to be taken as insults.

So the first comment did or did not solve this issue?

If not, try a reset. Press & hold the Power and Home buttons simultaneously, ignoring the red power off slider, until the Apple logo appears. Then release both buttons. This should not affect any content on the iPad, it is similar to rebooting your computer.

As long as you have checked everything that could possibly be configured to mess with this;

http://support.apple.com/kb/HT4085

then I would suggest that the next step is to restore the iPad to the factory settings and then set it up again. You could then restore it from a backup, but many folks are always superstitious that you could perpetuate the issue again by doing so.