Can't change user info (password check fails and proxy error)

[mrzapp]

I can't change my e-mail address on this page. I have logged out of the account, logged in again (so I know my password is correct), and when I attempt to submit a change I get this error:

Invalid password

Password is required to prevent unauthorized users from changing your email address and resetting your password. This field does not update your password!

And about half the time I even get this proxy error:

Proxy Error

The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request POST /account/.

Reason: Error reading from remote server