Spring-Social facebook using PagingParameters and page count

I'm using spring-social for facebook, <version>2.0.0.RC1</version> I have some problem using PagingParameters, I want to read all feed using pages.

this is the code:

PagedList<Post> page1;
    try {
        page1 = facebook.feedOperations().getFeed(new PagingParameters(50,0,null,null ));
        logger.info("* * * * * * * * * * * * * Page_size: " + page1.size());
        while (page1.size() > 0) {
           ...
            PagingParameters p =  page1.getNextPage();// 
            page1 = facebook.feedOperations().getFeed(p);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }

In this version seems work correctly (since the current stable version it dosen't work corretly).

Well, if I want to start read feed using form a date I have always a page.size()= 0;

I'm using "since" date as:

page1 = facebook.feedOperations().getFeed(new PagingParameters(50,0,myJavaDateTime.getTime(),new Date().getTime()));

I didn't find the way to set the date. How can I use the "since" date?

Thank you, any help is appreciated.