After setting the PrintTitleColumns to false, the TitleColumns range is reset.
Macro to reproduce:

Sub Main
	dim oCellRange(1) as new com.sun.star.table.CellRangeAddress
	dim oCellRangeColumns as new com.sun.star.table.CellRangeAddress
	dim oCellRange2 as variant
	
	oSheets = StarDesktop.loadComponentFromUrl("private:factory/scalc", _
                 "_blank", 0, dimarray())
	xSheet = oSheets.getSheets().getByIndex(0)

	oCellRange(0).Sheet = 0
	oCellRange(0).StartRow = 6
	oCellRange(0).EndRow = 8
	oCellRange(0).StartColumn = 6
	oCellRange(0).EndColumn = 8

	oCellRangeColumns.Sheet = 0
	oCellRangeColumns.StartColumn = 6
	oCellRangeColumns.EndColumn = 8
	oCellRangeColumns.StartRow = 5
	oCellRangeColumns.EndRow = 5

	xSheet.setPrintAreas(oCellRange())
	
	xSheet.setTitleColumns(oCellRangeColumns)
	xSheet.setPrintTitleColumns(false)
	
	oCellRange2 = xSheet.getTitleColumns()

	print oCellRange2.StartColumn & "  " & oCellRange2.EndColumn & "   " & _
			oCellRange2.StartRow & "  " & oCellRange2.EndRow
End Sub