At first I used the selenium version for the 2.48,firefox version of 37, when the automation opened the site, it can open normally.
Later, due to the Firefox self-detection update, the version is updated to 47, resulting in incompatible versions, when automation opens the Web browser, the site will never open normally. Later on the Internet to find solutions, has not been resolved, and then use the first download version of the 37 Firefox installation package, re-install the good.
So, if the automation environment to build OK, make sure that Firefox is set to not check the update (option-Advanced inside), or automatically update to the advanced version of the later version is incompatible.
Selenium: Https://pypi.python.org/pypi/selenium
Selenium-2.48.0.tar.gz (I was in the 2.48 version when I was selenium, and now it's in the 2.53 version)
Here are the selenium and the version of Firefox that I now know can correspond.
Selenium Firefox
2.45 36
2.48 37
2.53 46
Selenuim and Python test Web site, can only open Firefox but can't open the Web page solution