Why wont my suzuki dr 650 restart after pushing kill switch?

Possibly the kill switch did not return to the 'on' position. On my 2003, you press the kill switch once for 'off' and the button stays 'in'. Press it again to return in to the 'out' or 'on' position. Sometimes it sticks in the 'in' position and will not start (starter will not turn over).