Eu sou novo para o selênio. Estou executando testcases e estou recebendo a seguinte exceção:

org.openqa.selenium.WebDriverException: Unable to bind to locking port 7054 within 45000 ms
Build info: version: '2.28.0', revision: '18309', time: '2012-12-11 20:21:18'
System info: os.name: 'Windows 7', os.arch: 'x86', os.version: '6.1', java.version: '1.7.0'
Driver info: driver.version: FirefoxDriver
Command duration or timeout: 46.68 seconds
Build info: version: '2.28.0', revision: '18309', time: '2012-12-11 15:53:30'
System info: os.name: 'Windows 7', os.arch: 'x86', os.version: '6.1', java.version: '1.7.0'
Driver info: org.openqa.selenium.remote.RemoteWebDriver


at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:187)

Eu instalei o firefox versão 18, e tentei muita solução, mas ainda obtive o mesmo erro. Por favor, me ajude. Desde já, obrigado.