[Mimedefang] mimedefang will not start, mimedefang.sock unsafe

[zen187664]

I'm running mimedefang 2.70-1.el4.rf on centos 4.8, somewhere along the line
mimedefang has become mangled and will not start. When it worked the startup
sequence went like this:
# ./mimedefang start
Checking filter syntax: OK
Starting mimedefang-multiplexor:   OK  ]
Starting mimedefang:   OK  ]
Press any key to continue...
but now when I try to start mimedefang I run the command and the cursor just
drops to the next line, there's no confirmation text or anything. And
furthermore my mail log is throwing up this error message:
Milter (mimedefang): local socket name /var/spool/MIMEDefang/mimedefang.sock
unsafe
I've got a feeling this problem may have started after a spamassassin update
but I'm not 100% sure, and I'm not sure where to start in fixing this so any
advice would be appreciated.