I have modified the Top Poster script now it works at my Forum (http://ra.tribes.de/vb)
the fault was that there is an "if" Clause where it compares the Dates from $today and $toppostall (or so) and if this values were "!=" it requests the Stats from yesterday
but the Days are not equal on every new day !!! so it writes new stats every day
so I have coded another "if" Clause an in the functions.php I have rewritten the toppostall Funtion into two seperate functions one for posts and one for threads
now it works great

but when tubedogg don?t want to support his script anymore I will not post the modifications