You might be a bit confused. On the scenario page, clicking on "likes" (or the 'thumbs up' icon) tells Greenfoot that you like this scenario and the creator of the scenario is notified that someone likes it. When you receive a notification of "likes", there are two ways to check on it; through the scenario that person likes (look below and to the right of the scenario under the heading 'Who likes this?'), or through that members info screen (click on 'likes' to see the scenario that member likes).

The same thing also happened to me. When you first click on the Like-Button on a scenario, then you like it. But when you click a second time you don't like it anymore. I think that some one clicked Like and then clicked it again, but the website wasn't able to distinguish the Like and the "Dislike", so it showed you two likes

I'm going to test this on your Dialogs scenario. ; ) You should receive two likes, but when you look at it, no Likes should be there. Let's try this ...

@GameCode: Thanks, you are correct -- clicking once means you like the scenario. If you click again, you no longer like the scenario. I tried this on greep wars (http://www.greenfootgallery.org/scenarios/280), where I already signed up as "likes". Even though the button says, "I like it", clicking on it means you do not like it. I disliked and then reliked greep wars. I think the button wording is confusing and suspect that people may be clicking twice when they actually like the scenario. On the other hand, some people are probably just changing their minds... The email notification of two likes is definitely confusing. However, if I get two emails of like back-to-back, then I will know to ignore them.

The notifications of likes should now be fixed: you should only get a notification when someone likes your scenario, not when they dislike it. (This does mean it's still possible that when you get a notification about a like, it may not exist any more due to a subsequent dislike, but I don't plan to make notifications for dislikes). I've also fixed the colour of the like-it button so that it's green when you like a scenario and grey when you don't, which should help clarify what the current setting is.