I do believe the reason you had a fever was your body fighting those ugly critters!!
But, with all of your previous cleanses, where were these stones? I have only completed 6 cleanses and got very few stones out this last time which lead me to believe I am "clean." Now I am not so sure. I am wondering if I have those kind of stones still lurking in my body!!
How long did you wait in between cleanses? I wonder also if you had galbladder problems.