Command died with status 134Reply-To:

Hi

I have recently introduced some bug in my procmail scripts which results
intermittently in the following sender non-delivery notification:
Command died with status 134: "/usr/bin/procmail -a "$EXTENSION"". Command output: Aborted
 
However (and this might be because of some redundancy in my scripts) the mail is actually delivered to me.

Is there any clue in the above error message as to where I might look to fix this?

Thanks
Eric