Trying to better explain the problem...

Imagine that you and me are editing some data in a grid.
I'm inserting a bill number 1 with products 1 and 2.
You are inserting another bill (number 2) with produtcs 3, 4 and 5.
When I save my data, the products in your grid "is changed" - except the product in active row - and show my products.
This is only an incorrect display in grid, if you press up or down keys to change the active row, your products are showed correctly again. Even if you don't move to another row, when you save your data, the is saved correctly (with your products).

Forgive me if I can't explain correctly this time... I don't speak english much better.