Version:            (using KDE KDE 3.3.0)
Installed from:    Compiled From Sources
Compiler:          gcc-Version 3.3.4 Debian 1:3.3.4-7
OS:                Linux

The site www.deltatronic.de contains a normal version and a light version. The normal version is rendered fine in Konqueror 3.2 (Debian). Now, in the source I found 

function initMenu() {
  var doc = top.menu.window.document;
  doc.open();
  openFolder(0);
}

and a frameset is defined by 
<frameset cols="203,*" frameborder="no" frameSpacing=0 onLoad="parent.initMenu()">

  <frameset frameSpacing=0 rows="120,*" frameborder="no">
    <frame name="logo" src="logo.html" frameborder="no" scrolling="no" marginwidth="0" marginheight="0"> </frame>
    <frame name="menu" src="menu.html" frameborder="no" scrolling="no" marginwidth="0" marginheight="0"> </frame>
  </frameset>
  <frameset frameSpacing=0 rows="120,*" frameborder="no">
    <frame name="kopf" src="kopf.html" frameborder="no" scrolling="no" marginwidth="0" marginheight="0"> </frame>
    <frame name="hauptfenster" src="starthome.html" frameborder="no"> </frame>
  </frameset>
</frameset>

So on loading the frameset, the function initMenu() is called, calling essentially top.menu.window.document.open()
I would think - although I don't know why they call parent.initMenu() and not plain initMenu().

Anyway, Konqueror 3.3 opens a new window all the time on this site, and I can't use the "normal" version any more :(