We recently pushed live a (pretty major) fix for some account issues that were happening on Curse. If you were having problems logging in (receiving a server error), or problems activating your account, your account should now be fixed.
If it is not, or you have another problem, please let us know by sending us a message, or, if you cannot login, drop an email to bugs[at]curse.com.
Thanks for everyones patience in helping us identify this problem.