add: } else gRightMouseButtonDown = false; 
context: function TreeOnMouseDown(event){    // Detect right mouse click and change the highlight to the row    // where the click happened without loading the message headers in    // the Folder or Thread Pane.    if (event.button == 2)      ChangeSelectionWithoutContentLoad(event, event.target.parentNode);}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/349a0aed0b0192fd36ca0d15516f07cd63da3606/msgMail3PaneWindow.js/clean/mailnews/base/resources/content/msgMail3PaneWindow.js