data getting skipped when adding new rows

If I add information one line at a time (click + button and type in the info for that line and then click save) I haven't seen an issue. The data gets added to the database everytime. If you try getting several lines to add and then save sometimes the data gets lost. Here's the steps I took:

click + button and type in the info line1
click + button and type in the info line2
click + button and type in the info line3
click + button and type in the info line4
click + button and type in the info line5
click save button.

I've had several instances where the resulting grid on refresh only had line 1,3,4,and 5. Line 2 simply didn't make it.

Then I tried adding in the data for line 2 again and the add failed. I tried adding it a 3rd time and it still failed. There wasn't any error message though. The grid simply refreshes and does not show the data for line 2.

I looked in the database and the record was not there. I added it via SQL to the database directly and then the grid displayed the information correctly AND let me add new lines. Anyone see this behaviour?