Using MSIE 4.01, or 5.5SP1 (didn't try other versions) as a client to perform a multipart/mixed text/file upload with multiple files, there are some serious problem under php 4.06 + apache 1.3.20, statically builded on a linux glibc 2.1.3/egcs 1.1.2.

In a "--enable-inline-optimization" build, apache segfaults regardless of configuration option (tried almost any mix of these, with or without magic quotes, --enable-mbstr-enc-trans etc)

Instead, in build 
./configure' '--with-mysql=/usr/local/' '--with-gd' '--with-png-dir=/usr' '--with-jpeg-dir=/usr' '--with-curl' '--with-zlib' '--with-apache=../apache_1.3.20'
it almost works, as upload works normally, but php fails to set in $HTTP_POST_VARS any variable that comes inside the form after the file selector.
so

<form action="upload.php" method="post" enctype="multipart/form-data">
<input type="hidden" name="var1" value="1">
<input type="hidden" name="var2" value="2">
<input type="file" name="file[]">
<input type="file" name="file[]">
<input type="hidden" name="var3" value="3">
<input type="submit" name="var4" value="4">
</form>

would fail to set $HTTP_POST_VARS["var3"] and $HTTP_POST_VARS["var4"]