I like the conditional sum wizard with one exception. I can't edit the
resulting formula without invalidating it. The wizard adds a { to the front
of the formula and a } at the end of the formula. When I attempt to edit the
formula the { and the } disappear and the formula no longer functions. Even
if I add the { and th } back it still doesn't work.

How can I edit a conditional sum wizard formula without invalidating its
functionality.