I solved this problem by adding the first page outside of the while loop and setting the scale type to none...
printJob.addObject(printDataGrid, FlexPrintJobScaleType.NONE);
while (printDataGrid.validNextPage) {
printDataGrid.nextPage();
printJob.addObject(printDataGrid, FlexPrintJobScaleType.NONE);
}
printJob.send();
If you are interested in my full solution to printing a datagrid, see the answer to my question about adding a top margin to the print job... 19164992