Uploads from Windows 7
 

We can upload attachments to the forum perfectly all right from Windows XP workstations, but attempts from Windows 7 produce timeouts and only smaller files can be uploaded. The problem happens in both IE8 and Firefox 3.6.3. In fact, an HTTP upload from Windows 7 to a Joomla site on the same server also times out. Uploading to both sites works if the browser is runs from Windows XP.

Server Environment:
Windows Server 2003
Apache 2.2.6
PHP 5.2.5
vBulletin 3.8.4PL1

Workstation:
Windows 7 Enterprise with latest updates and network drivers
IE8, Firefox 3.6.3
Windows Firewall turned off
Symantec Endpoint Protection (turning off does not make a difference)

Smaller files, under 500KB, can be uploaded all right but files larger than 1MB fail. The sizes of the uploaded files are considerably smaller than the maximum sizes set in the Attachment Manager and the PHP settings - and everything works from Windows XP using the same automatic proxy configuration script for the LAN.

Settings from php.ini:
max_input_time 3600
max_execution_time 3600
upload_max_filesize 512M
post_max_size 512M
memory_limit 1024M

PHP error log:
[19-May-2010 10:21:49] PHP Fatal error: Maximum execution time of 3600 seconds exceeded in D:\www\production\forum\newattachment.php on line 14

This does not make sense for a 2MB file because the same file can be upload from XP in 10 seconds. Therefore the upload has hung but the server keeps counting.

I used Windows 7 to upload from public internet to the same server and that also timed out. Is Windows 7 getting confused in its interaction with proxy servers or the other way round?