StrongTypingException when setting column value

Question

Can anyone please tell me why I get a StrongTypingException when ASSIGNING a value to a column in a strongly typed DataTable? (I understand why I get it if I were to READ the column with DBNull value)

In the example below I'm trying to assign a value from one DataTable to another (all columns in the example are of type Int32). I can assign a value to the 'newOrderRow.items' column but when I do the same with the 'newOrderRow.debcode' column an Exception is thrown! Why?!

Some of the things I've tried so far (without any luck):
- Assign hard coded value instead of 'calclineRow.debcode'
- Call newOrderRow.SetdebcodeNull() before assigning another value
- Changed DefaultValue property on 'debcode' column in 'orderrows' table from DBNull to -1 and it STILL throws the Exception and says it's DBNull !!!

myDataSet.orderrowsRow newOrderRow;

foreach (MyDataSet.calclinesRow calclineRow in myDataSet.calclines)
{
    newOrderRow = myDataSet.orderrows.NeworderrowsRow();  //Create new 'orderrows' row

    //Assign values from one DataTable to another
    if (!calclineRow.IsitemsNull())
        newOrderRow.items = calclineRow.items;  //calclineRow.items == 1. Assignment successful
    if (!calclineRow.IsdebcodeNull()) 
        newOrderRow.debcode = calclineRow.debcode; //calclineRow.debcode == 556. Assignment raises System.Data.StrongTypingException ! (See message below)


    myDataSet.orderrows.AddorderrowsRow(newOrderRow);
}

/*Exception Message:
=====================

System.Data.StrongTypingException: The value for column 'debcode' in table 'orderrows' is DBNull. 
---> System.InvalidCastException: Specified cast is not valid. 
at MyProject.MyDataSet.orderrowsRow.get_debcode() in Q:\MyProjFolder\DataSets\MyDataSet.Designer.cs:line 21680
*/

Answer 1

SOLVED. Sorry, my bad.

I forgot that I was doing things with the 'debcode' column in the OnColumnChanging event handler on my DataTable. When I disabled that it all worked as it should.

Thanks anyway!