Updating DataRow throws Exception 0xC0000005

[Shade]

Hi guys,

I'm facing a very puzzling problem and thought maybe someone here could help. It's been driving me nuts, really.

I'm developing a Windows CE application (to be deployed in Windows CE 4.2 core) and my emulator is running Windows CE .NET v4.10 (build 908). I don't have a device with me now where I could test the software, unfortunately (that's still being arranged).

One of the code bits is a button to consolidate data, merging rows in a DataTable:

 private void btnConsolidar_Click(object sender, System.EventArgs e)
 {
 	for( int j=0; j < dataTable.Rows.Count; j++ ) 
 	{
 		DataRow row1 = dataTable.Rows[j];
 		String ean = (String)row1["ean"];
 		String cod = (String)( ( row1["codigo"] == null ) ? "" : row1["codigo"] );
 
 		int idx;
 		for( idx=j+1; idx < dataTable.Rows.Count; idx++ ) 
 		{
 			DataRow row2 = dataTable.Rows[idx];
 			if( ((String)row2["ean"]) == ean || (cod != "" && ((String)row2["codigo"]) == cod )) 
 			{						
 				long q1 = long.Parse((string)row1["quant"]);
 				long q2 = long.Parse((string)row2["quant"]);
 
 
 				if( bConferencia ) 
 				{
 					if( (string)row1["quant1"] == "0" ) 
 					{
 						string q = (string)row2["quant1"];								
 						//row1["quant1"] = q;
 						dataTable.Rows[j]["quant1"] = q; // CRASH!
 					}
 					if( (string)row1["quant2"] == "0" )
 						//row1["quant2"] = (string)row2["quant2"];
 						dataTable.Rows[j]["quant2"] = (string)row2["quant2"];
 				}
 
 				row1["quant"] = q1+q2;
 										
 				// remove a fileira copiada
 				dataTable.Rows.RemoveAt( idx );
 				//dataTable.AcceptChanges();
 				// row1 = dataTable.Rows[j];
 
 				// compensa a fileira removida
 				idx--;
 			}
 		}
 	}
 				
 	dgItens.DataSource = dataTable;
 	dgItens.Refresh();
 }

Please forgive the commented extra code, I've been adding and removing scaffolding looking for the problem.

What this does is something like this: suppose you have three rows, thus:

A 0 0 7
B 4 3 0
A 0 0 3
C 1 5 0
A 2 2 0

It consolidates the same products to:

A 2 2 10
B 4 3 0

It works when you only have one product repeated (i.e., only one row1 is updated). However, if there are several repeated products,

A 0 0 7
B 0 0 5
A 2 2 0
B 4 3 0

the system crashes with a native exception (code 0xC0000005, which research shows is an illegal memory access exception) when I try to update the second row in the table (line marked "CRASH!", above). Note that the first update goes well! Also, if I set it up with only one product repeated, press the button, set it up with another product repeated, and press the button again, it works.

I'm guessing it has to do with the way DataTable updates its rows, but so far, I've had no luck figuring the problem out. I'll greatly appreciate any help I can get!

Thanks in advance,

Shade.