php 4.3.2 + mysql 4.0.14 + apache 1.3.14 + openssl 0.9.6 + RedHat 6.1

I believe everything is installed correctly, but I only recently upgraded php and mysql. I added the LoadModule and AddModule lines and followed all the other install instructions (but really, I was just upgrading from 4.0.x to 4.3.x, so most of it was already in my httpsd.conf). When I fire up apache, there's no complaints; but when I try to access a php page, it tries to download it instead of viewing it. And when apache shuts down, it says that it can't remove mod_php4.c, so it looks like it's not getting loaded. I looked in my libexec for libphp4.so, and it's right there (and has a recent timestamp, telling me it's probably the new version, and not the old one). What should I look for? I know mysql is running, because I can log into it from the command line client. My apache error log is bare. There's no messages about php at all until I shut down. Dave