Any Rails change this morning?

I have 5 working rails sites. This morning, 3 of them stopped working, 2 of those being production sites that hadn’t been touched in days or weeks. All three now give the “500 Rails application” error from .htaccess, and they all quit writing to any of their logs (fastcsgi.crash, dev, production). There’s the anonymous “0 bytes received” error in the apache error log.

I did all the troubleshooting I could find online: perms on public/tmp/logs, ruby path, db & environment check. Console works, and writes to the logs. Fastcgi from the command line exits gracefully and writes to the logs.

Any other ideas for what to check? Anyone else have this happen today?

Rails v1.2.1 was released recently. My DH server is still running 1.1.6, but maybe DH updated yours to 1.2 (which had a bug) or 1.2.1, and your sites are incompatible with it.