sorting & paging problem

I am using TaminoClient API.

//sample code1 (2 results return)
taminoClient.setPageSize(2);
taminoResult = taminoClient.query("/TOPIC[//ParentID=514 and //TopicID!=514]",2);


//sample code2 (all results return???why???)
taminoClient.setPageSize(2);
taminoResult =TaminoClient.query(/TOPIC[//ParentID=514 and //TopicID!=514] sortby (.//upDateTime desc),2);



Can’t I use “sortby” and “page” mothed together?