Over zealous counter

Now that I've 'discover' the .shtml extension, started to experiment the
CounterFilter.  It worked fine on a single file, say
/User/Overview.shtml.  However, when I then put the filter on the
dicrectory /User, I found the counter started to increase by 3, instead
of 1.  Suspecting that it might be because of the counter I put on the
index file /User/Overview.shtml, I deleted the CounterFilter from
Overview.shtml.  But the problem is still there.  Every time I reload
the file /User/Overview.shtml, the counter increases by 3.  

Any idea?

-weiping