title: Firefox browser cannot restore page when navigated back in selenium webdriver
body: <p>I am using selenium webdriver with Firefox .</p>
  
  <p>driver.navigate().back();</p>
  
  <p>I  browse through  pages and when I navigate back through page , I get following exception.In Browser it says Document expired.</p>
  
  <p>org.openqa.selenium.StaleElementReferenceException: Element not found in the cache - perhaps the page has changed since it was looked up
  Command duration or timeout: 23 milliseconds
  For documentation on this error, please visit: <a href="http://seleniumhq.org/exceptions/stale_element_reference.html" rel="nofollow">http://seleniumhq.org/exceptions/stale_element_reference.html</a>
  Build info: version: '2.21.0', revision: '16552', time: '2012-04-11 19:09:00'
  System info: os.name: 'Windows 7', os.arch: 'x86', os.version: '6.1', java.version: '1.6.0_20'
  Driver info: driver.version: RemoteWebDriver
      at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
      at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
      at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
      at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
      at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:175)
      at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:128)
      at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:459)
      at org.openqa.selenium.remote.RemoteWebElement.execute(RemoteWebElement.java:245)
      at org.openqa.selenium.remote.RemoteWebElement.getText(RemoteWebElement.java:141)
      at run.DriverImpl.startScrapingFromThePage(DriverImpl.java:48)
      at ui.SAFSPUserInterface.startButtonClicked(SAFSPUserInterface.java:311)
      at ui.SAFSPUserInterface$1.actionPerformed(SAFSPUserInterface.java:62)
      at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
      at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
      at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
      at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
      at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
      at java.awt.Component.processMouseEvent(Component.java:6263)
      at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
      at java.awt.Component.processEvent(Component.java:6028)
      at java.awt.Container.processEvent(Container.java:2041)
      at java.awt.Component.dispatchEventImpl(Component.java:4630)
      at java.awt.Container.dispatchEventImpl(Container.java:2099)
      at java.awt.Component.dispatchEvent(Component.java:4460)
      at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)
      at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
      at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
      at java.awt.Container.dispatchEventImpl(Container.java:2085)
      at java.awt.Window.dispatchEventImpl(Window.java:2478)
      at java.awt.Component.dispatchEvent(Component.java:4460)
      at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
      at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
      at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
      at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
      at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
      at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
      at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)</p>
  
  <p>The page contains Ajax and javascript calls . Can anyone help me in this?</p>