I think I found it, the error was in the router
// Joomla replace before route limitstart by start but without SEF this is start !
if ( isset($query['limitstart'] ) ) {
$limitstart = (int)$query['limitstart'] ;
unset($query['limitstart']);
}
if ( isset($query['start'] ) ) {
$start = (int)$query['start'] ;
unset($query['start']);
}
if ( isset($query['limit'] ) ) {
$limit = (int)$query['limit'] ;
unset($query['limit']);
}
if ($start !== null && $limitstart!== null ) {
vmdebug('Pagination limits $start !== null && $limitstart!== null',$start,$limitstart);
//$segments[] = $helper->lang('results') .',1-'.$start ;
} else if ( $start>0 ) {
//For the urls leading to the paginated pages
// using general limit if $limit is not set
if ($limit === null) $limit= vmrouterHelper::$limit ;
$segments[] = $helper->lang('results') .','. ($start+1).'-'.($start+$limit);
} else if ($limit !== null && $limit != vmrouterHelper::$limit ) {
//for the urls of the list where the user sets the pagination size/limit
$segments[] = $helper->lang('results') .',1-'.$limit ;
}