Itunes store connection problems

[bondbill2k2]

With the purchase of Ipads in school we decided to set them up from my workstation, I installed itunes, connected the Ipad and the device needs to be setup for the first time, the problem is Itunes will not connect to the Itunes store, in a secound of clicking itunes store the message iTunes could not connect to the iTunes store make sure your network connection is active and try again.

Well the connection is fine to the internet and I can use my iPhone using the same proxy to access the iTunes store with the built in app, I have ran a diagnostics but im still pretty stumped why I have this problem.

Microsoft Windows 7 Business Edition (Build 7600)
OEGStone DH55TC
iTunes 10.5.0.142
QuickTime not available
FairPlay 1.13.35
Apple Application Support 2.1.5
iPod Updater Library 10.0d2
CD Driver 2.2.0.1
CD Driver DLL 2.1.1.1
Apple Mobile Device 4.0.0.96
Apple Mobile Device Driver not found.
Bonjour 3.0.0.10 (333.10)
Gracenote SDK 1.9.3.494
Gracenote MusicID 1.9.3.106
Gracenote Submit 1.9.3.136
Gracenote DSP 1.9.3.44


Current user is an administrator.
The current local date and time is 2011-11-04 15:39:15.
iTunes is not running in safe mode.
WebKit accelerated compositing is enabled.
HDCP is not supported.
Core Media is supported.

Video Display Information

Intel Corporation, Intel(R) HD Graphics


**** External Plug-ins Information ****

No external plug-ins installed.

iPodService 10.5.0.142 is currently running.
iTunesHelper 10.5.0.142 is currently running.
Apple Mobile Device service 3.3.0.0 is currently running.

**** Network Connectivity Tests ****

Network Adapter Information

Adapter Name: {64FE76FA-CE14-4671-8143-1D4C51C8CFAC}
Description: Intel(R) 82578DC Gigabit Network Connection
IP Address: 10.26.112.51
Subnet Mask: 255.255.248.0
Default Gateway: 10.26.112.1
DHCP Enabled: Yes
DHCP Server: 10.26.112.3
Lease Obtained: Fri Nov 04 08:17:23 2011

Lease Expires: Wed Nov 09 08:17:23 2011

DNS Servers: 10.26.112.3
10.26.112.4

Active Connection: LAN Connection
Connected: Yes
Online: Yes
Using Modem: No
Using LAN: Yes
Using Proxy: No
SSL 3.0 Support: Enabled
TLS 1.0 Support: Enabled

Firewall Information

Windows Firewall is off.

Connection attempt to Apple web site was successful.
Basic connection to the store failed.
An unknown error occurred (-50).
Connection attempt to Gracenote server was successful.
iTunes has never successfully accessed the iTunes Store.

Edit:
We are running sophos on all clients but sophos shows no signs of interference, alerts of suspicious behaviour.

[linkazoid]

I had to allow itunes.apple.com in our Smoothwall yesterday because of this.

Can you allow this in your filter?