[CentOS] cups drivers for printing pdf and tif

List,

I updated a gateway/router computer with Centos 5.6 and lost the ability
to print pdf and tif files with the command "lp -d printer img.tif"

This new unit replaced a Fedora 5 system that had been working well, and
is still able to print pdf and tif files withing the same network.

I have other Centos 5.6 gateway's at different facilities that print the
pdf and tif files without a problem.  All of these 5.6 systems have been
updated without a problem.  

hpijs-1.6.7-6.el5_6.1.x86_64 has already been installed.

I am at a loss in trying to see the difference between my 5.6 machines
and would appreciate some advice as to where to look.

Thanks much for your help.

Greg Ennis