The number of Jewish dating Web sites continues to grow, with all of them claiming a high success rate. But how many of them help build real relationships and how many create problems and hinder relationships? While there are dozens of Jewish dating sites, three - JDate, Dosidate and Frumster - appear to stick out. And each of them has its problems. JDate, which boasts a membership of more than 600,000, has a unique policy of "once you check in, you can never leave." Of course these are not JDate's official words, but it does admit that once you join, there is no official link that will delete your profile. In fact, if you get married (and many have through this site), you then have to telephone JDate in the US to request your profile be suspended (not deleted). Amanda Haley of London was told her profile was still seen on JDate almost four months after she married, despite calling its Beverly Hills office on four occasions. "Even then I had to threaten them with legal action to remove it," she said. "Two years later, my profile is still on their site. It is not available for viewing, but why should they be allowed to keep those details?" The answer, of course, is marketing. "Even though we do take the profiles off-line... we do not delete them in case someone wishes to return," a JDate spokesman told The Jerusalem Post. But he did concede "it does help us to promote JDate as being the world's largest Jewish dating site" because these profiles are still officially on the site. Moreover, not everyone on JDate is Jewish, and sometimes you will even find Christian missionaries or Jews for Jesus who have no problem writing what they believe in their profiles. Others feel a Jew is generally a good person to marry and so they also sign up. What checks are done to ensure that the more than 600,000 profiles are all Jewish? JDate says it has no way of knowing who is Jewish and therefore does not have any policy on the matter. "If someone says they are Jewish," the spokesman says, "we believe them, unless we are alerted to something." DOSIDATE was established in July 2001 by Grayson Levy, whose goal was to help serious Orthodox singles in Israel find a partner and get married. Later that year, he launched the Frumster site with the same focus, but this time aimed it at Orthodox singles in North America. Frumster grew rapidly because it was free and it was promoted throughout various Orthodox communities. But as the site grew, so did the work load and Levy sold it three years later. The new Frumster ownership charged members a fee to send and read a "received message." They invested the money back into the business by upgrading the Web site. Although Grayson eventually charged a small fee for sending messages on the Dosidate site, he set it up so that if you receive a message from a member and you do not have a paid subscription, you can still read the message and reply, unlike Frumster. As Dosidate began to grow, Grayson decided it was taking too much of his time to run and last July sold it to Elraz Sela of Tel Aviv, who has kept the same features, format and price. He claims as many as 15,000 members are active. When Grayson set up Dosidate, he added a filter that prevented "bad language or inappropriate words." Sometimes, however, it does not operate as it should. Last summer Mordechai Marks of Jerusalem was in contact with Orit in New York. They exchanged several messages and Mordechai asked for Orit's telephone number. She responded positively with her number and the words "it would be lovely to talk to you." The problem was Mordechai did not receive the message. For some reason the filter had blocked it. Mordechai wrote another message to Orit, but she did not receive it. He thought it was strange that contact just stopped without any reason and wrote a final message wishing her good luck. Of course the filter blocked that one, too. Two months later, Mordechai wrote to Na'ava in Beersheba (another member of Dosidate). She responded with her telephone number. He wrote again asking if they could just exchange some messages first to see if there was a desire to talk and then maybe meet. But Na'ava did not get that message. He wrote again and again the messages did not reach her. Mordechai then noticed in his Dosidate "sent" message box that she had replied to both messages. But he did not get them. So he wrote to Dosidate explaining the problem and was told there was a bug in the site. The next day the messages were in his inbox. Mordechai then noticed that Orit in New York had also replied to him, but he did not get the message. He wrote to Dosidate and once again the reply was "thank you for bringing this bug to our attention," and the next day the message was in his inbox. Of course it was Orit's telephone number and "it would be lovely to talk to you," but dated more than two months earlier. Mordechai telephoned Orit and explained why it had taken more than two months to call, but Orit replied: "I am now going out with someone." Mordechai still thinks she did not believe him. Dosidate director Elraz Sela said the messages were blocked because of banned or inappropriate language, but later admitted the filter may have acted incorrectly. Sela also said the purpose of the filter is "to prevent missionaries and others like that who purposely target Jews." He added that Dosidate invests a great deal of money in keeping these undesirables off the site. ON FRUMSTER, if a member writes a message, the recipient must also have paid the membership fee to read it (unlike Dosidate where the recipient can read the message for free and reply for free). But as some people choose not to pay this fee unless they see the "perfect profile," you can write to one of them unknowingly and receive no reply. Or the person has left the site even though his profile with a picture is still up there, even though the site has a "delete profile" link. Another problem with Internet dating sites is the possibility of false profiles. David in Tel Aviv placed a phony profile of a young woman - including a photo - on Frumster because he "wanted to see how many messages she would receive." And she received "dozens and dozens." There is no guarantee that the person responding to your message is actually who he says he is. And of course, stories about the "date from hell" and the "complete nutcase" abound. Despite the bugs and problems, however, the Jewish dating sites have proven successful and many people have found marriage partners through them.