PHP Warning: socket_select(): 9 is not a valid Socket resource

```
What steps will reproduce the problem?
1. sudo php -q server.php
2. 192.168.1.15/client.html
3. refresh chrome explorer some times

What is the expected output? What do you see instead?
Stay connected to the chat.
Some times it disconnects from the chat, and on the server side it shows
messages
PHP Warning: socket_select(): 6 is not a valid Socket resource in
/var/www/websocket/server.php on line 15
PHP Warning: socket_select(): 7 is not a valid Socket resource in
/var/www/websocket/server.php on line 15
PHP Warning: socket_select(): 8 is not a valid Socket resource in
/var/www/websocket/server.php on line 15
PHP Warning: socket_select(): 11 is not a valid Socket resource in
/var/www/websocket/server.php on line 15

What version of the product are you using? On what operating system?
Downloadad client.php and server.php from project home 13th June
Server side Ubuntu 11 + Apache2 + PHP5
Client side Windows XP SP3 + Chrome 12

Please provide any additional information below.
I haven't checked the code yet, as it's my first time working with sockets.

```

Original issue reported on code.google.com by `jgom...@gmail.com` on 15 Jun 2011 at 10:37