I'm having the exact same problem, and I'm also suspicious of the issue that lead to the lockout. I'm pretty sure I had to enter the code twice to set it, and I used the same pin I always use, how could I enter it wrong twice? Either way the only solution I've seen is to erase via find my iPhone. I'm ok with that, but there is no way to connect to the internet with the iPad on lock!
Try and force iPad into Recovery Mode:
1. Turn off the device: Press and hold the Sleep/Wake button for a few seconds until the red slider appears, then slide the slider. Wait for the device to turn off.
If you cannot turn off the device using the slider, press and hold the Sleep/Wake and Home buttons at the same time. When the device turns off, release the Sleep/Wake and Home buttons.
2. Connect USB cable to computer, leave the other end alone
3. Press and hold the Home button down and connect the docking end of cable to iPad
4. Continue holding the Home button until you see the "Connect To iTune" screen
5. Release the Home button
6. Open iTune
7. You should see "iTunes has detected an iPad in recovery mode"
8. Use iTune to restore iPad
Note: You need to be patient and repeat the above many times to recover your iPad