Summary:
nofilter option doesn't work for mode='summary' when mode='form' is also used on same page
Detailed Description:
When you use the nofilter option in summary mode, and you also have a
mode="form" above the summary, the summary's filter form does not completely
disappear.
This is because the question submit form needs to be cleared.
Fix:
function.default_summary.php
Add an else clause to if( $filter != '' ) ...
} else {
$smarty->clear_assign('formstart');
}