|On the main page and your Control Panel there is an ONLINE MEMBERS box. If your login name is listed twice it simply means that you have logged in using all lower-case letters and your login name has capital letters in it.
Being listed twice does not cause any harm, but to stop it from happening simply log in Case Sensitive.
For example my login name is:
...but if I log in as
...it will show up twice.
To see the correct way to type your login name check out your profile or at the top of your Control Panel.