Activation HELP!!!

I'm having a hard time activating Unity Free ver. I can't connect to the server, I try manually activating, but i get error on the website.

"Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@unity3d.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Apache/2.2.3 (CentOS) Server at store.unity3d.com Port 443"

Any ideas?