title: Python Selenium click() doesn't work
body: <p>I am trying to automate a web file downloading program with Selenium in Python. But I have some difficulties in clicking one particular button with Selenium: The program succeeds in leading to this url '<a href="https://www.sec.gov/Archives/edgar/data/1467373/000119312510235847/0001193125-10-235847-index.htm" rel="nofollow noreferrer">https://www.sec.gov/Archives/edgar/data/1467373/000119312510235847/0001193125-10-235847-index.htm</a>', but it cannot click on the button of the first document (d10k.htm). The button is defined as 'formbuttonElement' in the following code and I tracked it by Xpath. In addition, I used both click() and .send_keys(Keys.SPACE) methods, but they didn't work. </p>
  
  <p>Can someone have a look at this problem?</p>
  
  <p>Thank you!</p>
  
  <pre><code>from selenium import webdriver
  from selenium.webdriver.support.ui import WebDriverWait
  import unittest
  import os
  
  
  class LoginTest(unittest.TestCase):
   def setUp(self):
      fp=webdriver.FirefoxProfile(r"C:\Users\sxc\AppData\Roaming\Mozilla\Firefox\Profiles\x5i7u4m7.profileToolsQA")
  
      fp.set_preference("browser.download.folderList",2)
      fp.set_preference("browser.download.manager.showWhenStarting",False)
      fp.set_preference("browser.download.dir", "D:\doc1")
      fp.set_preference("pdfjs.disabled", True)
      fp.set_preference("plugin.disable_full_page_plugin_for_types", "application/pdf")
  
      fp.set_preference("browser.helperApps.neverAsk.saveToDisk", "application/pdf")
  
  
      self.driver=webdriver.Firefox(firefox_profile=fp)
      self.driver.get("https://www.sec.gov/edgar/searchedgar/companysearch.html")
  
  
   def test_Login(self):
      driver=self.driver
  
      cikID="cik"
      searchButtonID="cik_find"
      typeID="//*[@id='type']"
      priorID="prior_to"
      cik="00001467373"
      Type="10-K"
      prior="20101231"
      search2button="//*[@id='contentDiv']/div[2]/form/table/tbody/tr/td[6]/input[1]"
  
  
      documentsbuttonid="documentsbutton"
      formbuttonxpath="(//a[contains(@href,'/Archives/edgar/data/')])[1]"
  
  
      cikElement=WebDriverWait(driver,30).until(lambda driver:driver.find_element_by_id(cikID))
  
      cikElement.clear()
      cikElement.send_keys(cik)
  
  
      searchButtonElement=WebDriverWait(driver,20).until(lambda driver:driver.find_element_by_id(searchButtonID))
      searchButtonElement.click()
  
      typeElement=WebDriverWait(driver,30).until(lambda driver:driver.find_element_by_xpath(typeID))
      typeElement.clear()
      typeElement.send_keys(Type)
      priorElement=WebDriverWait(driver,30).until(lambda driver:driver.find_element_by_id(priorID))
      priorElement.clear()
      priorElement.send_keys(prior)
      search2Element=WebDriverWait(driver,30).until(lambda driver:driver.find_element_by_xpath(search2button))
      search2Element.send_keys(Keys.SPACE)
      time.sleep(1)
  
      documentsButtonElement=WebDriverWait(driver,20).until(lambda driver:driver.find_element_by_id(documentsbuttonid))
      documentsButtonElement.click()
  
      formElement=WebDriverWait(driver,30).until(lambda driver:driver.find_element_by_xpath(formbuttonxpath))
      formElement.send_keys(Keys.SPACE)
  
  
  
   def terdown(self):
      self.driver.quit()
  if __name__=='__main__':
  unittest.main()
  </code></pre>