William,
The same thing happened to me. I used a safety pin (pried open a bit)
and a magnifying glass to move the internal button around until it
popped back into it's correct position and the rapid advanced stopped.
The same problem has happened more than once, so I have learned to be
very careful to push the button as lightly as possible.
Hope that solution works for you.
Lee Kouns
South Lake Tahoe