rem: var doDisable = !(enableHTTP11.selected && enableKeepAlive.checked); 
add: var prefString = enablePipelining.getAttribute("prefstring"); var isLocked =  parent.hPrefWindow.getPrefIsLocked(prefString);  var doDisable = !(enableHTTP11.selected && enableKeepAlive.checked) || isLocked; 
context: function checkPipelining(){  try {    var enableHTTP11 = document.getElementById("httpVersion11");    var enableKeepAlive = document.getElementById("enableKeepAlive");    var enablePipelining = document.getElementById("enablePipelining");    var doDisable = !(enableHTTP11.selected && enableKeepAlive.checked);    enablePipelining.disabled = doDisable;  } catch(e) {}}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/902f1923656f729646b4911a9f5388b816b356d8/pref-http.js/clean/xpfe/components/prefwindow/resources/content/pref-http.js