rem: if (fp.show() == nsIFilePicker.returnOK) PREF.setCharPref("browser.bookmarks.file", fp.file.path); 
add: if (fp.show() == nsIFilePicker.returnOK) { var path = Components.classes["@mozilla.org/supports-string;1"] .createInstance(Components.interfaces.nsISupportsString); path.data = fp.file.path; PREF.setComplexValue("browser.bookmarks.file", Components.interfaces.nsISupportsString, path); } 
context: function OpenBookmarksFile(){  const nsIFilePicker = Components.interfaces.nsIFilePicker;  var fp = Components.classes["@mozilla.org/filepicker;1"].createInstance(nsIFilePicker);  fp.init(window, BookmarksUtils.getLocaleString("SelectOpen"), nsIFilePicker.modeOpen);  fp.appendFilters(nsIFilePicker.filterHTML);  if (fp.show() == nsIFilePicker.returnOK)    PREF.setCharPref("browser.bookmarks.file", fp.file.path);}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/9421/9202da24770cb500f8995e71686bc6a8201e5a53/bookmarksManager.js/clean/suite/common/bookmarks/bookmarksManager.js