dbcbackup_interval() needs to pass through cron schedules that other plugins create. Instead, it overwrites.
function dbcbackup_interval($scheds) {
$cfg = get_option('dbcbackup_options');
$cfg['period'] = ($cfg['period'] == 0) ? 86400 : $cfg['period'];
$new_scheds = array('dbc_backup' => array('interval' => $cfg['period'], 'display' => __('DBC Backup Interval', 'dbc_backup')));
return array_merge($new_scheds, $scheds);
}
