What's currently going on here is ridiculous. Just stop pretending that you are able to provide a flashcard system.
There is iKnow and there is skritter. iKnow had to learn it the hard way that customer support is necessary. After they became a paid service there was hardly any customer support and a lot of people left. Now you can use their bug tracking system and expect that the bugs are fixed within a couple of days. If the service is unavailable you can follow on twitter.
The support of the skritter people is even better. Once I was stuck because of a problem in the data for one kanji. I got into contact with a person there within minutes and the problem was fixed after 2 or 3 emails a few hours later. This was a Sunday night.