Hi,
does this checkbox have an onclick javascript-handler attached to it?
if so, you might want to call the click() method on it:
${$cb}->{id} eq 'checkbox' and ${$cb}->click;
else you must set the value explicitly:
${$cb}->{id} eq 'checkbox' and ${$cb}->{value} = 'Yes', ${$cb}->{checked} = 1;
HTH,
-- Abe.