problem with poi and row height

[maxime_phan]

hello everybody,
I using POI to generate some report, and here my problem with my code:

row.createCell((short)2);HSSFUtils.createCell(row, (short)2,
CoordResponsable, cellStyle);
HSSFUtils.mergeCell(sheet, 8+i, (short)2, (short)4, cellStyle,
CoordResponsable);

with the function:
public static void mergeCell(HSSFSheet sheet, int iRow, short
startCell,
short endCell, HSSFCellStyle style, String value) {
HSSFRow row = sheet.getRow(iRow);
if (row==null) {
return;
}
sheet.addMergedRegion(new Region(iRow, startCell, iRow, endCell));
if (style!=null) {
row.getCell(startCell).setCellStyle(style);
}
if (value!=null) {
row.getCell(startCell).setCellValue(value);
}
}

public static HSSFCell createCell(HSSFRow row, short iPos, String
value, HSSFCellStyle cellStyle) {
HSSFCell cell = row.createCell(iPos);
cell.setCellValue(value);
cell.setCellStyle(cellStyle);
return cell;
}

in my cellstyle i have cellStyle.setWrapText(true);

when i do :
HSSFUtils.mergeCell(sheet, 8+i, (short)2, (short)4, cellStyle,
CoordResponsable);

my variable CoordResponsable is a string with many line
but the merged cell doesn't fit the data(the data are in the cell but
you can only see the first line and you have to click on the cell to
see all, I would like the row's height fit automatically with the
number of line)

any idea?
thanks in advance