Hello,

I don't think that it is a firewall problem nor is it a registry problem. IMO, you still have a MIME problem or your configuration settings in the "iDeploy Web Update" properties are incorrect.

Check the following first (but as I understand it, you already did)
http://www.lindersoft.com/forums/showthread.php?t=1286
http://www.lindersoft.com/forums/showthread.php?p=7790
http://www.lindersoft.com/forums/showthread.php?t=13687

You said that the web install worked fine. Both web update and web install make use of the same download technology. Can you download the first cluster file with Internet Explorer?

Friedrich