Thank you for the quick response.
Ctrl+F5 didn't relieve it (as that is how I always refresh during dev)... deleting the whole cache directory and all of the root.php pages, then replacing them all did for whatever reason work.
config.php exists... as does lang/English/common.php
Neither give any errors or output when I go to them directly. Reviewing the code of each in markup colors shows that everything seems to be correct in them (at least a basic level). To be sure, I downloaded the build again, and re-uploaded all of the files from scratch. Unfortunately I have gotten the same result. For thoroughness' sake, I just went through and installed it on another apache server (from a different webhost) and it has operated the same way - i.e. nothing past install.php works.
I think it must be something with my names or passwords, or something.
To test I simply made it as simple as I could, after deleting all of the database, and all elements of Pun from the server (including the /forums/ directory that I had created), I started over by uploading everything from the upload folder of the freshly downloaded punbb-1.2.15.zip file and created a new database through the cpanel.
dbname = test
username = tester
password = test
no prefix on table names
Made the config.php file and uploaded it.
Same result.
This is an Apache 1.3.36 (Unix) Server
w/ PHP 4.4.2 and MySQL 4.1.21-standard
Everything PHP/MySQL I've ever put on it has worked. I'm pretty PHP proficient, and I can't see any reason for this not to be working. Any other ideas?