It's in Javascript AwareIM/Tomcat/webapps/AwareIM/aware_ext/aware.js
Try locating in this file an occurrence of the top bar menu creation. You should be looking for something like this:
var folderMenu = new Ext.menu.Menu ();
(this should be inside an "if statement" that checks for the menu item type:
if (itemType == "folder")
{
....
var folderMenu = new Ext.menu.Menu ();
....
}
The fix is to add the following after the creation of the menu:
folderMenu.onMouseLeave = function () {};
if (itemType == "folder")
{
....
var folderMenu = new Ext.menu.Menu ();
folderMenu.onMouseLeave = function () {};
....
}
You need to refresh the browser after the fix.