return value of size() does not change when removing children of a collection. 

e.g. this does not work as expected:

{{{
   res.debug('###pre');
   res.debug('size ' + forum.size());
   res.debug('children ' + forum.list());

   var len = forum.size();
   for (var i=len-1;i>=0;i--) {
      var comment = forum.get(i);
      comment.remove();
      forum.removeChild(comment);
   }
   res.debug('###post');
   res.debug('size ' + forum.size());
   res.debug('children ' + forum.list());

---------- output ---------
###pre
size 3
children Comment#51006863,Comment#51006313,Comment#51005791
###post
size 3
children
}}}

this works as expected in the official helma 1.6.3. release.