And to answer my own posting... I have found updated versions of various RPMs that when installed together, make it work fine:
httpd-2.2.4
mod_perl-2.0.3
ImageMagick-perl-6.3.7-3
ImageMagick-6.3.7-3
The ImageMagick RPMs were built on CentOS4-i386 from the source RPM at:
ftp://ftp.imagemagick.org/pub/ImageMagi ... -3.src.rpm