Hi, I just wanted to let you know about a bug I've encountered several times.  It's really frustrating for me especially because I access your website at work.

Many times I'll be in the middle of a Review session and I'll go off to do something else on my computer (I test software so I can do the reviews in the background as I'm testing other stuff).

However, inevitably I will encounter a situation where it looks like your site has timed out my login session. and when I click the next card button (or the End button I get this message:

"The page at http://kanji.koohii.com says:
Oops! Invalid JSON response.
<OK>"

Then I click <OK>.  Well at this point I think  I'll just END the review session.  I click END button and I get this message:

"Are you sure you want to navigate away from this page?
Wait you may lose a few flashcard answers if you leave the page now.
Select CANCEL to stay on this page, and then click the END button to complete this review session.
Press OK to continue, or Cancel to stay on the current page.
<OK> <Cancel>"

If I click <Cancel> I just get the same messages over and over.  After flipping each card I get the "Invalid JSON" message.  And if I hit the End button I get the "Are you sure you want to leave" message.

The worst part is If I actually End the review (click <OK> in that message) and leave.  I get booted to a login screen.  then if I re-login sometimes (I haven't figured out why it gives me a corrupted results screen.  With like "you got X out of Y correct" but the items I covered may not show beneath it.  And if I go back to review I noticed that my number of reviews that are due goes down, making me think those answers registered in your system, but, if I enter the review session again I will get duplicates.

I'm enjoying using your site to go through the RTK system and I look forward to many improvements... Thanks for the great service.

-Matthew