I think I found a little bug. I can reproduce it with your demo
with the Opera 12 and the IE10 browser.
reproducing steps for the demo:
click "add new record"
move to page 2
move back to page 1
now you have an empty row in the grid
If you press the create button twice, the validation message will show, but if you move the page (you CAN move the page), the validation message won´t show.