I realized that I’d managed to update to Sarge (v 3.1) mostly without noticing. I should have pinned my packages to woody (3.0) but didn’t realize, which meant that I went through the update process without actually noticing. This led to a number of odd problems. In particular I hadn’t disabled a number of backports, which led to difficulties with apache, php, mysql and postgresql. This happened because the ports were set up to target woody (3.0) rather than Sarge (3.1).
However I have now properly upgraded to Sarge on marilac. Hopefully this will be a suitably satisfactory release and will provide many hours of happy uptime. 