I am not sure that this is a bug, but for some reason, when attempting to get the file owner of a file getpwuid() fails (used in this context):

$uid = fileowner($path);
$owner = posix_getpwuid($uid);

Fileowner() returns either 0 or 1028, and getpwuid fails. The 0 of course false would mean the file doesnt exist, but using the same variable ($path) in other functions such as fileperms() etc do not fail and return the proper data. 

Situation:
$path = "/home/";
$uid = fileowner($path);
$owner = posix_getpwuid($uid);
$owner_name = $owner['name'];

I have tried the same situation with valid filenames (instead of directories).

all extensions are enabled and configure line is:
'./configure' '--target=i386-redhat-linux' '--prefix=/usr' '--with-config-file-path=/etc' '--disable-debug' '--enable-pic' '--enable-inline-optimization' '--with-apxs=/usr/sbin/apxs' '--disable-static' '--with-exec-dir=/usr/bin' '--with-regex=system' '--with-gettext' '--with-gd' '--with-jpeg-dir=/usr' '--with-png' '--with-zlib' '--with-db2' '--with-db3' '--with-gdbm' '--enable-debugger' '--enable-magic-quotes' '--enable-safe-mode' '--enable-sysvsem' '--enable-sysvshm' '--enable-track-vars' '--enable-yp' '--enable-ftp' '--without-mysql' '--with-xml'

(as phpinfo() says it is)