JM, can I please please send you my project. I've posted a few threads now. I've been having major issues with my data adapter and my mster/detail datarelation etc. If i post my project will you please have a look and help me.

I have a Result_Header(master) table which has a productid as a foreign key and when I select a product in a dropdown the result_header datagridview displays records from the resul_header table which matches the selected product, and a Result_Detail(child) table. When I add a master record and click save, my code goes and looks in a prodtest table for existing tests on the selected product and adds new rows to the child table.

Now if I add 2 new records and look at the result_header (say primary keys 5565 and 5566) and result_detail table the child table has the correct values in the resultid field(so 4 new records for each parent has 5565 and 5566) which is the ID fields value from Result_header. when I add a 3rd record(5567), for some reason, it overwrites 5565 with 5566's info in the master table and 5567's with 5566's info. Resul being 5565 now has eight chil records, 5566 has 4 and 5567 has 0.

It's quite confusing but if you see my project you'll know what I mean