I did not know this but apparently it is normal to disappear from the rankings of Google for a while after having appeard up there among the top 30. Since yesterday I have a little concerned about the site how to improve brain power not even being in the top 100 list. However, after browsing about in the forums a little I was assured that this happens at the beginning of every page. I will be able to confirm whether this is true or not when my other site Tenerife Rent a Car gets some backlinks and starts appearing on Googles search rankings. Until then I will continue my backlinking strategy and see what happens.