My Facebook account keeps asking me to log in at random times?

[Anastasia]

I could be bowsing through my news feed, or I might have just been looking at another tab (with Facebook still logged on and running in it's tab) and when I come back to my account it tells me to log in, more specifically "this page cannot be accessed until you log into your account". this has happened about 5 or 6 times in the past week. sometimes it asked me to type one of those skewed photo tests then enter my e-mail and password. and sometimes it tells me to type in a confirmation code that has been send to my phone, and on one occasion I was made to identify people tagged in certain photos (which was difficult because some of them where when people tag other people who aren't even in the photo)
I was wondering why this keeps happening to me, sometimes is sais that it's happening to confirm that I am a person not a computer, but other times it's just random
Extra Info:
my Facebook account is set to remember my password and I have my page as a favourite on my browser so when I open Facebook, I don't log in, I have suspicions that this is why I keeps asking me to prove my identity or confirm something but it has never been a problem before

[Zan]

seems like someone else is logging into your account from another computer. thats why facebook is logging you out at your computer. might just be an error but its worth changing your password just to be safe.

[Molly Kim]

I believe someome else knows your password or they hacked your account. They keep logging in from ther device and this is when Facebook asks you to confirm your identity. The hacker will usually stop logging into your account for a period of a few hours to ensure he or she is safe before entering your account. Change your password immediately! I hope I helped you.

Help me? http://answers.yahoo.com/question/index;...943AAEcwOA

[ReB94]

Do you delete cookies or clear the browser history while you are logged in? If not then, someone else is definitely logging in to your account.

[Angeleyes]

It seems like someone knows your password or else they hacked your account. Clear your cookies and browser. Change your password.