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Still here? We know that bugs are frustrating and annoying things. We also
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more information you give us now, the more likely it is that we'll be able
to help.

What steps will reproduce the problem?
1.In Firefox, try to find the selects in webpage, then click the option every the 
 select, at the last, Failed; But In Google， It is OK!
2.this is my code:
(1)selects=browser.find_elements_by_tag_name("select")
(2)for Uselect in selects:
    Uselect.click()
    time.sleep(3)
    print Uselect.find_elements_by_tag_name("option")[1].click()
    time.sleep(3)
    print"good job"
3.Runing the Code,The Firefox is failed; Chrome is ok;

What is the expected output? What do you see instead?
Webdriver is good test tool,So i think The Code can running whether the Firefox or
Chrome. 

Selenium version:
OS:
Browser:Firefox / Chrome
Browser version: Firefox :25.0.1  Chrome: 28.0.0


Please provide any additional information below. A sample reduced test
case, or a public URL that demonstrates the problem will intrigue our merry
band of Open Source developers far more than nothing at all: they'll be far
more likely to look at your problem if you make it easy for them!