[Mimedefang] upgrading 2.51 to 2.57

[NFN Smith]

I'm in the process of upgrading several servers from MD 2.51 to 2.57.

The servers are Debian Sarge, running sendmail 8.13.8, and the 2.57 
installation was done by Debian package, taken from the Testing branch.

As far as I'm aware all the MD config settings on each server are 
identical, and we have one server that's been running for several weeks 
on a 2.57 installation.

However, on one server, something is amiss, and I'm not seeing how to 
fix it.

On this particular box, when MD starts, it allocates slaves to inbound 
messages, but when 10 slaves are allocated, then I start getting error 
messages that look like:

    mfconnect: No free slaves: Need 1, found 0

And we start temp failing messages.  Senders see:

   451 4.3.2 Please try again later

On this box, the sendmail configs are somewhat different from the boxes 
where things seem to be working correctly.

I checked the Changelog, and found the incompatibility note about 
detect_and_load_perl_modules(), and added that to my filter file, but 
following a restart of MD, I'm not getting any different results.

Any idea of what I'm missing?

Smith