Secret Question Answer - UPM Membership Provider
Commerce UPM Member ship provider always treats the security question answer as case insensitive. While creating the user , UPM Membership provider does ToLower() of the provided secret question answer and also converts the supplied answer to lower case while doing comparison. If both Create and Forgot password functionality goes through the same UPM Provider, we will not face any issues. If we are creating the users through different API's like commerce runtime or web services, keep this as one of the design constraints.