ESS not updating through Squid Proxy

As mentioned in this topic: https://www.wilderssecurity.com/showthread.php?p=988308#post988308, ESS does not update with a transparent Squid Proxy running. When the proxy is disabled, updates work perfectly.

I've watched the logs of the proxy and all seems to be well:

Code:

Time - IP Address - URL
20:19:31 192.168.0.10 http://u24.eset.com/eset_upd/update.ver 
20:19:32 192.168.0.10 http://u24.eset.com/download/engine3/em002_32_l2.nup

Can anyone suggest anything?

 

Do you have proxy server configured properly in the general proxy server setup or you have it configured within an update profile? Note that for each update profile you can choose to use either general proxy server settings or settings customized for a particular profile.

 

Given it's transparent, configuration shouldn't be an issue (and wasn't with NOD32).

The main proxy settings window detects no proxy and has the "Use Proxy Server" box unticked while the update profile uses the "use global proxy server settings" option. I've tried with the straight "Do not use a proxy server"; doesn't make a difference.

As mentioned in this post of mine, identifying a nontransparent proxy outside the local network results in a successful update.

 

Has anyone else experienced this? I'm slightly concerned it could be a misconfiguration on my part, but I can't see where given that NOD32 updated fine (and still does on other computers on the network perfectly).

 

Attached are my exported configuration settings - still haven't found a solution for this.

 

Hate to quadruple post, but I'm still experiencing this.

Is there anything I could provide/run to troubleshoot this?