I've just recently started to have a problem in definition practice; when I click 3 for "got it", sometimes not only the current definition is marked correct, but the NEXT one appears and is immediately marked correct as well. It doesn't happen all the time, but it does also happen sometimes if you click above the grading buttons. Initially I thought there was a problem with my mouse, but since it happens with the "3" button I think it's probably a problem with the Flash. (My reasoning is that the "3" button should immediately vanish upon showing the next item, so even if I double-clicked by mistake it shouldn't reveal and grade the next item.)
The main problem is that, once you've seen the definition, you don't always know whether you would have gotten it correct or not. So, to be safe, I mark them wrong and that potentially wastes time on unnecessary reviews.
This is on Chrome 11.0.696.34 on Windows XP, Flash player version 10,2,154,25.
James