Its not possible to help you out without knowing the keyword..it might be the case that you have searched out with quotes and it really make a difference..the best you can do at this point of time is again finding out the keyword status with other free keyword tools and the one i can tell you is http://www.serpanalytics.com/tools/top_keywords If everything is still fine then you should check out googling with your keyword every day or even in every couple of hour. As when you are very new to google it shows you up with your keyword but then google takes your website away from that position to check your website for every single possibilities...