I have 2 NetBSD servers with apache 1.whatever and php4.2.3 installed.
They share the same configurations and were built with the same commands.

Apparently the only difference between the two resides in a change in 
www/php4/Makefile.common:

CONFIGURE_ARGS+=        --enable-experimental-zts
CONFIGURE_ARGS+=        --with-tsrm-pth

Apparently this did NOT cause a version bump. (4.2.3nb1 perhaps?)
These lines should be removed at once.

I want you to know, I've spent the whole afternoon trying to understand 
what was wrong with the scripts.
Things got better when I (exasperated) checked the binary files (diff of 
mod_php4.so files) and they turned out different. phpinfo() showed a 
difference was in the configure agruments.

In particular, with the "new experimental" version the difference in 
behaviour I noted were as follow:

- file_exist() behaved as if it was in a different directory: files in 
local dir (./whatever) were NOT available, while with full path 
(/home/httpd/docs/whatever) they were. Note that 
fopen(file_with_relative_path) opened the file perfectly.
- symlink() behave in similar ways: symlink("/netbsd", "netbsd") failed, 
symlink("/netbsd", getpwd() . '/netbsd') worked.
- unlink() of a symlink resulted in removing the TARGETED file, not the 
symlink itself. You can imagine my happiness when vital read-only files 
were removed `:|

Now I copied the (non-experimental) binary in the other place, and 
everything's working as it should :D

-- 
--- TLD
"There is no Good, one thorough, there is no Evil, there is only Flesh"
   [Pinhead]