Occasionally applications will not close using “X” on upper left of window.

I'm using Ubuntu 14.04 64bit on a Dell Latitude Laptop with an Intel Core i5 and 4G RAM installed.

Description: Ubuntu 14.04 LTS
Release: 14.04

unity:
  Installed: 7.2.0+14.04.20140416-0ubuntu1
  Candidate: 7.2.0+14.04.20140416-0ubuntu1
  Version table:
 *** 7.2.0+14.04.20140416-0ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status

Seemingly randomly I will not be able to close an application using the "X" button of the upper left of the screen when "Show the menus for a window - in the window's title bar" option is selected in the appearance settings. Sometimes it requires multiple clicks, but usually when this happens I have to right click the application icon on the quick launcher and select "quit" to close the window. This has occurred on multiple applications "firefox", "nautilus", "pithos", and "software center" are the most recent that I can remember for example, and I am assuming this is an issue with Unity on my system.

I expect windows to always close within a short amount of time after clicking the "X".
This is a new issue that I did not have using Ubuntu 12.04. I am being sufficiently patient with allowing plenty of time (several seconds) for applications to close before clicking anything else again.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity 7.2.0+14.04.20140416-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Fri Apr 18 10:10:24 2014
InstallationDate: Installed on 2014-04-13 (4 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Beta amd64 (20140326)
ProcEnviron:
 LANGUAGE=en_US
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)