rem: var navTB = document.getElementById("nav-bar"); navTB.parentNode.appendChild(printPreviewTB); 
add: var navToolbox = document.getElementById("navigator-toolbox"); navToolbox.parentNode.insertBefore(printPreviewTB, navToolbox); 
context: function showPrintPreviewToolbar(){  toggleAffectedChrome(true);  const kXULNS =     "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";  var printPreviewTB = document.createElementNS(kXULNS, "toolbar");  printPreviewTB.setAttribute("printpreview", true);  printPreviewTB.setAttribute("id", "print-preview-toolbar");  var navTB = document.getElementById("nav-bar");  navTB.parentNode.appendChild(printPreviewTB);}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/ac0eb2260dd2066c42dc02e2d88ddb1416681605/browser.js/buggy/suite/browser/browser.js