We've been getting a fair number of reports of the following problem when trying to activate new accounts:
"Incorrect activation code, please double check the url sent to your email address."
If you received this error when you first registered, can you let us know what email client (or if you read your email on the web, which website), browser and operating system you're using, and also, if you recall, whether you clicked on the URL in the email message or copied and pasted it into a browser window? Was there anything else unusual in the process? Did you have to click it twice? Is it possible someone else who has access to your email had previously activated your account for you?
If you're trying to register now and receiving this message, in most cases your account is activated despite the error message. Please go to the front page of the site and try using your userid and password to log in. If that doesn't work, please send an email to email@example.com from the email address you used to register, and we'll try to help.