twitter verification failing after account rename

My twitter account used to be `@syscomet` but is now `@philpennock`, after I renamed. I got the Keybase notification that the proof verification was now failing, so issued `keybase prove twitter philpennock` and said yes to the overwrite prompt.

Proof is up at:
https://twitter.com/philpennock/status/603141976649760768

(An earlier attempt was missing the `Verifying myself:` prefix)

Keybase is unable to see that proof. The only variance in it is the insertion of the leading `@KeybaseIO` for reply-based proof, to avoid spamming my followers with a non-status-update; that mode used to be supported.

What have I done wrong, please?

Start by reproducing the failure with `keybase prove twitter philpennock` and inspect the proof at the linked Twitter status, including the `Verifying myself:` prefix and leading `@KeybaseIO` reply. Done means Keybase recognizes the renamed account's proof or clearly reports why this proof format is unsupported.

Written by the indexing model from the issue text.