I was adding stuff to this page, typing in names of games when I typed in something that was already in the list. I were using my keyboard only to type in Shadowrun then select Shadowrun Returns with the arrowkeys and enter when I get the popup that says "Object already in table" and then the page refreshes with no warning.
When I try it in Firefox it starts refreshing as soon as I hit enter to select the game, in Chrome it is when I close the popup.
This only happens when using the keyboard for selecting search results, not when clicking.
This can be a bit annoying if you have added lots of thing already and haven't saved yet.