Create a zul page containing a grid (see _autopagingTest.zul); assign a GroupsModel (SimpleGroupsModel) to it; set autopaging="true" mold="paging" vflex="true" as grid's parameters. Show the page in a browser, then resize the browser page vertically so that the last visible item in the grid is a group head (see Page 1.png), leaving about a half blank row under it. Move to page 2 using the paging component arrow at the grid's bottom. Content in page 2 will start flickering, continuously adding/removing (in page 2) the last group head of page 1 (see Page 2A.png, Page 2B.png).