rem: if (this.mTxMgrShell) rootShell.observerService.Notify(this.mTxMgrShell.mDataSource.mDataSource, "vfd-focus", this); 
add: if (this.mTxMgrShell) { try { rootShell.observerService.Notify(this.mTxMgrShell.mDataSource.mDataSource, "vfd-focus", this); } catch (e) {  } } 
context:   focusVFD: function ()  {    var rootShell = vxUtils.getRootShell();    // for a focused vfd, send "vfd,url"    // vixenMain.vxShell.mFocusObserver.Notify({ }, "window_focus", ("vfd," + this.mParams.documentURL));    rootShell.mFocusedWindow = window;        if (this.mTxMgrShell)       rootShell.observerService.Notify(this.mTxMgrShell.mDataSource.mDataSource, "vfd-focus", this);  },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/8852c23f1bacfa3897d66b4c2199a124aa5bda8d/vfd.js/buggy/extensions/vixen/resources/content/vfd/vfd.js