gecko1 - 6:06 am on Feb 5, 2011 (gmt 0)
I have seen the results from GP go up and down all of the time. I have only made a few minor changes since creating the page. One day I will be ranking high and then the page won't be found anywhere. Recently it has been ranking for different keywords that I wasn't specifically targeting. I think Google must still be experimenting a lot with this. I think you can only follow the basic guidelines, watch the stats and then just forget it for a while.