Hi,
I implemented a config setting for this today, so if you put this in your user.config file, then after you upgrade to the next release of mojoPortal it will use a case insensitive check on the password security quesiton answer:
<add key="AllowCaseInsensitivePasswordQuestionAnswer" value="true" />
The default will remain case sensitive, but this setting will allow you to make it work as you would like.
Hope that helps,
Joe