> My server is CentOS 4 or 5, I forget which, running PHP 4.1.0 with...



You are trying to use a class constant ("const"). It seems like you
are trying to do some OOP (Object Oriented Programming), i don't think
"const" was not introduced into the PHP OOP model until php5.

Either replace "const" with define('const_name','value') or update
your php version to php5.