Flashcards function is not working now.
I am using safari on Mac.
It works fine for me in Safari. Please try opening the flashcard set a few times if it is giving you problems. We did upload a significant change to the flashcards today so there may be some caching issues.
Thank you for your quick reply, Mark.
Although I have sill this problem, I will wait and see for a while.
Yes! You did upload a significant changeto the flashcards!
Now I realized how it works!
Cool!
Sorry, we need to provide some instructions! 
You must click anywhere in the white area to flip the card. You can flip back and forth as much as you want. You can click Oops or Got it and change status with one click. Editing of hints and phrases is also possible right on the flashcard.
Here are the complete instructions, http://www.lingq.com/learn/ja/forum/3/6824/.
Mine still aren’t working. I’m using Internet Explorer with Windows 7. Nothing happens when I click in white space, nor when i click the arrows on the top right hand corner that I assume should scroll through the cards, and the bottom of the pop up says there’s an error on the page.
There looks to be a problem with IE. We are trying to figure out what it is. Sorry about that. Hopefully, it won’t take long.
I had the same problem with IE 8.0, too. Now downloading safari for PC 
Here is the error code:
Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; InfoPath.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)
Timestamp: Tue, 1 Jun 2010 06:42:11 UTC
Message: Expected identifier, string or number
Line: 716
Char: 5
Code: 0
URI: Login - LingQ
problem solved, thank you!