[exim] Error in system filter

Hi

We are running exim-4.63 on Solaris 2.8, using SpamAssassin 2.63. We
feed all our incoming mail through SpamAssassin using the built-in code.
We then run the messages through a system filter to replace the Subject:
header, if SA has marked the message as spam. A significant proportion
are causing this message to appear in the logs:

internal problem in system filter: failure to transfer data from
subprocess: status=0000 readerror='No such file or directory'
Error in system filter: internal problem in system filter: failure to
transfer data from subprocess: status=0000 readerror='No such file or
directory'

We are probably getting 2 or 3 like this a minute. There was a somewhat
similar problem reported back in January 2004, but I couldn't see an
explanation in the archives. Does anyone have any idea what this might
be? By the way, there's no problem with disc space - all discs have at
least 750MB free.

Any suggestions gratefully received

Max Caines
IT Services, University of Wolverhampton
Wolverhampton, West Midlands WV1 1SB
Tel: 01902 322245 Fax: 01902 322699