firstly ,
i was in Security and Login section , and was watch my " where you logged in " i was see Miranda logged in for facebook as " Andriod "
after some minutes , facebook suddenly logged me out as suspecusse activity , and said that i may wrote my password in a different site and asked me to confirm my activity. and to change password
so , why this happened ? in your last change you may did some mistake ? and why facebook appear that i logon from Andriod ? by this facebook thinks that i use 2 machines in same time , and it's not allowed for there securty reasons , it's bad to logon and chat from 2 machines in same time
please check this problem if happened with anyone else