9 out of 10 times this is due to a simple typo. Your passwords are case sensitive, meaning PASSWORD is different from password and PassWord. Also extra characters, even an unseen space after your username or password will deny you access. Be sure there are no blank spaces before or after your password and/or user name. This is the number one cause of confusion and unsuccessful login attempts.
1. Be certain you are entering them in exactly as you have chosen them, they are Case Sensitive.
2. If all else fails, email us. Include your username and password, along with your full name and email address you used when you originally registered. Email all of the above info to: firstname.lastname@example.org for assistance.