Zoneminder: Got unexpected memory map file size

I'm trying to capture video from a device that's 640x480 24bit color, but I'm getting this in /var/log/syslog:

ERR [Got unexpected memory map file size 9217192, expected 36865192

Google-ing for this doesn't turn up anything except the Zoneminder source code; but it turns out that this is caused by too small a setting in /proc/sys/kernel/shmmax. This is explained the Zoneminder FAQ.

After updating my /proc/sys/kernel/shmmax to the recommended 128MB, it works just fine...