This is how my experience with google has been. IT seems like everytime i make progress and get listed for certain keywords, two weeks later i am no where to be found. I can't figure it out. Has anyone experienced the same thing?
Just because you don't see your listing doesnt mean it's not being shown elsewhere to other searchers. The best way to track your keyword progress is to use Google Webmaster Tools and monitor what your 'average rank' is each week/month.