Created attachment 24647 [details] Sample test case methods setRowBreak and setColumnBreak do not work in 2007 XML file format. This works in xls files.
Created attachment 24648 [details] Spreadsheet which shows row and column break
Created attachment 24649 [details] XLSX w.o row and column break
I am using 3.5 final
Fixed in r1139266 - Excel didn't see breaks because some important xml attributes were missing. Should work now. Yegor
*** Bug 47102 has been marked as a duplicate of this bug. ***