The most common cause of this issue is when the username and/or password has been entered incorrectly in the accelerator settings. Your username must be entered in the following format:
Access 1 Users enter: yourusername@access1net.net
Netbypass Users enter: yourusername@netbypass.net
You can access the accelerator settings dialog screen by left clicking on the accelerator icon and left clicking settings. Next, click the connection tab (second tab from the left). Once, you have entered your credentials correctly restart your computer and reconnect to the Internet for the new credentials to take effect.