recipe suddenly failing

Running procmail v3.22 2001/09/10 on ubuntu 8.04. The following recipe has 
been unchanged and working well since I ran RedHat 7.3 (yeah, *that* 
long) until yesterday.

               :0 c
               /home/holtzm/mail/backup

               :0 ic
               | cd /home/holtzm/mail && rm -f dummy `ls -t msg.* | sed -e

As of now it no longer delivers any copies to my backup file, even tho I 
have received 600+ emails in the last day or two. As an experiment I tried

               :0 c:
               /home/holtzm/mail/backup

which didn't work either. What completely snows me is why after working 
all these years, would it suddenly give up the ghost.

Any help, pointers, suggestions appreciated.

--

-- 
Bob Holtzman
"If you think you're getting free lunch,
  check the price of the beer"