[kh99]

Well, that line of code adds a check for stick or not depending on the value of an option. So I'm not sure if you always want to check the prefix, or only if you're also checking for sticky. In the first case, you could do this:

// Set if only Sticky threads are shown
$stickysql = ($instance['options'][$cfg_type . '_sticky'] ? "AND thread.sticky = 1 " : '');
$stickysql .= " AND thread.prefixid = 'id' ";

or if you only want to check the prefix if it's also sticky, do this:

// Set if only Sticky threads are shown
$stickysql = ($instance['options'][$cfg_type . '_sticky'] ? "AND thread.sticky = 1 AND thread.prefixid = 'id' " : '');