Correct answer but screen freezes

One of the courses I am doing is “Discovering French Bleu”, creator MadameRivero, who is not on the Forum. My problem today with this course is when I type in the correct answer (and I know absolutely it’s correct) the screen freezes. It doesn’t happen every time though. The only way I can get out of it is by typing “memrise” up in the browser which takes me back to my home page. Here is the link to the course: http://www.memrise.com/course/132971/discovering-french-bleu-2/
Any ideas?

Could you give us some examples of words which causes your browser to freeze?

This is one of them, which is on Level 6 … Quel âge as-tu. The first time I type it in it shows as incorrect (when I know it isn’t), I then type it in again and it shows as correct (by lighting up with green background) - but at that point the screen freezes. There were a few others which I can look for (again) and post if you wish. Thanks.

Take 2 @Joshua - I made a mistake although there is still another weird thing going on. I just went back into Level 6 again and French is: “Quel âge a-t-il” and not “Quel âge as-tu” as I stated earlier. It is very strange though when I type it the second time “Quel âge as-tu” - it turns it green - as if it’s correct. It’s at that point that the screen freezes.