Procmail IFS error

All appears to be well with my new Exim configuration except the
following Procmail-related error...

1997-07-01 07:58:52 0wj4OK-00002H-00 ** |IFS=' ' && exec
/usr/local/bin/procmail -f- || exit 75 #ned <win-support@???\
s.net> D=userforward T=address_pipe: "IFS='" command not found for
address_pipe transport
1997-07-01 07:58:52 0wj4OK-00002K-00 <= <> R=0wj4OK-00002H-00 U=exim
P=local S=1503
1997-07-01 07:58:52 0wj4OK-00002H-00 Error message sent to ned@???


The last entry in "MAIN CONFIGURATION SETTINGS" is...
procmail_pipe:
driver = pipe;
command = "/usr/local/bin/procmail -d ${local_part}",
from_hack,
user = exim

And the last entry in "DIRECTORS CONFIGURATION" is...
procmail:
        driver = localuser,
        transport = procmail_pipe;

Any clues would be welcome.
Am using the latest version of Exim with a BSDI 2.1 system.

Ned Schumann