Using 2 NetBSD 1.4.2 machines running PHP4.0.2 and 4.0.3pl1 respectively are running the same script which looks like this:

<?
set_time_limit(0);
[socket]
[connect 0.0.0.0 port foo]
[send info]
[recieve info]
[send instructions] 
echo "beginning reception.\n";
while (1){
      read($net_fd,$net_buf,2048);
      echo $net_buf;
}
[close]
?>

I acknowledge the ugliness of such code, it should yet be functional. In PHP 4.0.2 it works as expected, recieving all information back, and echoing to html or console (was tested on console). In PHP 4.0.3pl1 it recieves no information at the actual code portion listed above. It returns no error, but reads no information.

The service was tested with plain ol' telnet and with a c program, neither of which had any difficulty on either machine. Both PHP's are compiled with sockets enabled. Also works on RedHat 7.0 PHP 4.0.2.