Dennis and Cameron, thanks a lot for your suggestions. After unsuccessfully trying several configurations for the /etc/hosts file, I restored an old backup version. That version worked like a charm and fixed all the localhost and printing problems I was having.
The backup seemed to have been generated by some sort of script (it didn't look anything like the example in the Networking-Howto). I forgot that I had modified the /etc/hosts file back in January when I tried (unsuccessfully) to get Junkbuster to run. I just didn't make the connection between my modification of /etc/hosts and my printing problems. Once again, thanks.
