I'm sure you guys are very busy with this issue, and I hate to add to the pile, but it appears that if a security question answer has a foreign character it is being rejected as invalid.
A dear friend is from Sweden and his security answer was comprised of the name of a local city. He has now been locked out until Monday after providing the correct answer because the nonstandard character ( รถ ) wasn't recognized.
It accepted his answer when setting up his account. I'm not sure if anything can be done, but we had to try.. 3 days without SL is an eternity!
~M