In the Window that use a field type Memo,
cant save the data.

I saw this difference:

if (e.getNewValue() == null && e.getOldValue() != null
&& e.getOldValue().toString().length() > 0) {// some editors return "" instead of null
mTable.setChanged (true);
differnce ----->>>> mTable.setValueAt (e.getNewValue(), row, col, true);
}
else