I've been having interesting problems with the DataGridView, so I thought I'd look at the Northwind example to see if the problems exist there also or if it is something I'm doing different (what I expected to find).

I ran the program, selected Customer ANATR and Invoice 10308. When I went to the Properties page, I changed the Qty in the first line to 6 and hit Save. It gave me an error that the discount could not be 0 (IsEmpty() issues are another story). I changed it to 1 and it saved fine. I moved to the second line, changed the Qty to 6 and hit save, and did not get an error for the Discount being 0. I got curious. I set a breakpoint in OrderDetailRules.CheckRulesHook to see what is happening. It turns out that this.CurrentRow stays at 0. So when I enter data in row 1, it validates row 0 again. I sure hope I'm missing something here. I realize that the demo does not contain bulletproof validation, but this has me concerned.

I look forward to you pointing out the error of my ways,
Jeff