files to avoid double scroll bar.
Be warned, it means replacing (modifying) one core script of Postnuke, please make a backup first of all files that will be replaced.
In addition template.html of each theme (coppermine) needs modification.

Tested with 0.726
Files also for 0.750 (not tested !)

Changes in header.php of PostNuke :
Added this function
*********************************************************
echo "<script type=\"text/javascript\">
function adjustIFrameSize (iframeWindow) {
  if (iframeWindow.document.height) {
    var iframeElement = parent.document.getElementById
(iframeWindow.name);
    iframeElement.style.height = iframeWindow.document.height + 40 + 'px';
    iframeElement.style.width = iframeWindow.document.width + 10 + 'px';
  }
  else if (document.all) {
    var iframeElement = parent.document.all[iframeWindow.name];
    if (iframeWindow.document.compatMode &&
        iframeWindow.document.compatMode != 'BackCompat') 
    {
      iframeElement.style.height = 
iframeWindow.document.documentElement.scrollHeight + 5 + 'px';
      iframeElement.style.width = 
iframeWindow.document.documentElement.scrollWidth + 15 + 'px';
    }
    else {
      iframeElement.style.height = 
iframeWindow.document.body.scrollHeight + 5 + 'px';
      iframeElement.style.width = 
iframeWindow.document.body.scrollWidth + 15 + 'px';
    }
  }
}
</script>\n\n";
*********************************************************
just before "if(isset($additional_header))"

Changes in template.html
Replaced <body> with <body onload="if (parent.adjustIFrameSize) parent.adjustIFrameSize(window);">

Change in index.php of pnCPG
Replaced :
echo "<iframe id='pnCPG' src='$url'  width='100%' height='1200' marginwidth=0 marginheight=0 frameborder=0></iframe>";
with :
echo "<iframe id='pnCPG' name=\"postwrap-content\" src='$url'  width='100%' height='1200' marginwidth=0 marginheight=0 frameborder=0 onload='parent.scrollTo(0,0);'></iframe>";
include("footer.php");
