Maximizing Safari window with selenium sometimes fails

Question

I'm using Selenium RemoteWebDriver to run tests written in Java on a remote MacBook. I maximize the browser window using:

  driver.manage().window().maximize();

This works 100% of the time for Chrome, Firefox and IE11. But with Safari this seems to fail about 30% of the time. I thought maybe there could be some extra synchronization issues with Safari so I tried:

  Thred.sleep(10*1000);
  driver.manage().window().maximize();
  Thred.sleep(10*1000);

Unfortunately this did not help. I'm getting the error message:

TimeoutException: Timed out awaiting response to command "maximizeWindow"

Does anyone know how to solve this?

Edit: Since it might matter, here's the URL and Capabilities I'm using to create the driver:

  DesiredCapabilities caps = DesiredCapabilities.safari();
  LoggingPreferences logPrefs;
  logPrefs = new LoggingPreferences();
  logPrefs.enable(LogType.BROWSER, Level.ALL);
  caps.setCapability(CapabilityType.LOGGING_PREFS, logPrefs);
  RemoteWebDriver driver= new RemoteWebDriver(new URL("http://serverIP/wd/hub"), caps)