DataTable problems with pagination and selection

[omainegra]

Hello, I have a DataTable with checkbox selection and pagination. The selection is retrieved from the Data Base so when the view is rendered the corresponding rows in the first page are marked, now when i change to page two the other rows that should be marked are not. This is normal or there is something wrong.

Thanks in advance

Apache Tomcat v6.0 y v7.0, Mojara 2.1.2 FCS, Primefaces 3.0M2.