I had a co-worker bring me an iPad this morning that was locked up. He was trying to send a mail, but the Send button would not light. Tried a hard reboot,(Home +Power - held it for over 30 seconds) and a soft reboot(Home button for 20 seconds). NEITHER WORKED!. Was a bit stumped, double pressed the home key and started to force close all unused apps. This (apparently) freed up enough memory and unlocked the unit. Very weird that the hard reboot (Home + Power for 10 seconds(or more) did not work