Michal:
I did and got this error:
EventDescription: Message: Unable to cast object of type 'CMS.Controls.DataPager' to type 'System.Web.UI.WebControls.DataListItem'. 
Stack Trace: 
at System.Web.UI.WebControls.DataList.GetItem(ListItemType itemType, Int32 repeatIndex) 
at System.Web.UI.WebControls.DataList.System.Web.UI.WebControls.IRepeatInfoUser.GetItemStyle(ListItemType itemType, Int32 repeatIndex) 
at System.Web.UI.WebControls.RepeatInfo.RenderVerticalRepeater(HtmlTextWriter writer, IRepeatInfoUser user, Style controlStyle, WebControl baseControl) 
at System.Web.UI.WebControls.DataList.RenderContents(HtmlTextWriter writer) 
at CMS.Controls.QueryDataList.Render(HtmlTextWriter output) 
at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) 
at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) 
at System.Web.UI.UpdatePanel.RenderChildren(HtmlTextWriter writer) 
at System.Web.UI.UpdatePanel.Render(HtmlTextWriter writer) 
at System.Web.UI.PageRequestManager.RenderFormCallback(HtmlTextWriter writer, Control containerControl) 
at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) 
at System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) 
at System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) 
at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) 
at System.Web.UI.HtmlFormWrapper.System.Web.UI.IHtmlForm.RenderControl(HtmlTextWriter writer) 
at System.Web.UI.PageRequestManager.RenderPageCallback(HtmlTextWriter writer, Control pageControl) 
at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) 
at System.Web.UI.Page.Render(HtmlTextWriter writer) 
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)