Running Woody or Sid? Looks like the maintainer of the ppp package borked
a script, it's trying to run keep instead of the desired operation.

/etc/modutils/0keep is a file that contains module info that should be
kept from kernel to kernel and dist-upgrade to dist-upgrade. It's not
something that should be run.

Check bugs on the ppp package:
http://bugs.debian.org/cgi-bin/pkgreport.cgi?pkg=ppp&archive=no

They may hed mor light on the subject.

Andrew S. Zbikowski | http://www.ringworld.org
"We can learn much more from wise words, little
from wisecracks and less from wise guys."
--William Arthur Ward