"Bad file descriptor" errors with dkimproxy.in as


Anyone here is using dkimproxy with postfix as a pre-queue filter?

I’m using it, and dkimproxy.in works for most of the time, but it dies for about 8% of mails that get through it with the following error:
dkimproxy.in: write error acknowledging accepted: Bad file descriptor”

Any idea of what does it mean?