Sadly, I had to change my PGP key. The old one (0180 31D2 2C1D 7C24) is revoked and is no longer valid.
Bottom line: don’t trust your hardware, always make good (offline) backups, test backups regularly.
Also, I have lost some of the more recently encrypted files (thankfully, these were copies of paper documents I still have).
The new master key’s fingerprint is A8D2 90A1 8D1E 6486. I will try to get my new key signed in person by the CACert.org folks ASAP.