OS: Win98 SE
Setup: php 4.4-dev Dec 10 8:29, no PHP related stuff in any Windows or System folder, php folder and sub out of zip unchanged except php.ini

Sorting out inst issues I stumbled over following behaviour:

Scenario a:
Dos Box, Current dir = dir containing php.exe, php.ini states a wrong extension dir, holding outdated exts
I say :"php.exe c:\abc\def.php" 
No complains about missing or wrong ext mods
this is a script doing socket stuff. It begins to run, opens, binds, listens to a socket, and recognizes a
connection request from a telnet client. Then it dies with a page fault on socket_read when the client wants to submit the first character. Oddly enough it gets as far but ok as the ext dir is wrong anyway.

Scenario b:
I fix extension_dir using "-dextension_dir=path" on the commandline. echo ini_get('extension_dir') shows
the correct location BUT: The script dies when it comes to reading the first character from the client

Scenario c:
I fix php.ini, just changing extension_dir to point to the correct location. Everything works fine.

Both extension_dir specs can be given rel and abs. Same symptoms.