Sencha paging plugin not working properly

Question

I am trying to implement a function with the Sencha "ListPage" plugin and work correctly, but in the following case I have an exception. The server sends the total number of lines, for example 10, but if I have a pagesize property configured with 11 lines, the plugin does not work. Here is a small piece of code with the implementation of the store:

store = Ext.create('Cicero.store.activity.Activities', {
            storeId: storeId,
            pageSize: 10,
            autoLoad: false,
            clearOnPageLoad: false
        });

This is the implementation of the plugin in the view:

            //LISTPAGING
        {
            xclass: 'Ext.plugin.ListPaging',
            autoPaging: true,
            loadMoreText : 'Loading more activities',
            noMoreRecordsText : 'All Activities loaded'
        }
    ],
    scrollable: true,
    onItemDisclosure: true,
    emptyText: 'No activities found',

Basically the problem is this: everything works correctly, but when the number of returned records is less than the page size, the plugin does not work.

Any clue?