Installation Error - Internet connection could not be established.

I'm running in to a server that can't get Sophos installed.  I keep getting the above error and the log shows the following

4:04:36 PM,Information,------------------ Beginning installation of Sophos Anti-Virus and AutoUpdate ------------------,
4:04:36 PM,Information,Setup version 3.1.3.279,
4:04:36 PM,Information,Command line: %TEMP%\1\sophos_bootstrap\setup.exe -server dzr-mcs-amzn-us-west-2-fa88.upe.p.hmr.sophos.com -token *****************,
4:04:36 PM,Information,Process security set successfully,
4:04:36 PM,Information,Setup program was run from %TEMP%\1\sophos_bootstrap,
4:04:36 PM,Information,Checking if Sophos Anti-Virus or Sophos AutoUpdate are installed...,
4:04:36 PM,Information,Starting wizard to collect information from user...,
4:04:41 PM,Information,Starting the install sequence.,
4:04:41 PM,Information,Checking for internet connectivity...,
4:04:41 PM,Success,Successfully connected to the URL http://dci.sophosupd.com/.,
4:04:41 PM,Information,Checking for internet connectivity...,
4:04:42 PM,ERROR,Failed to send a WinHttp request. The error code was 2148074278 (The message received was unexpected or badly formatted.).,
4:04:42 PM,ERROR,Failed to connect to the URL dzr-mcs-amzn-us-west-2-fa88.upe.p.hmr.sophos.com/.../ep.,
4:04:42 PM,ERROR,An internet connection could not be established.,
4:04:46 PM,Information,------------------ Installation program finishing with code 143 ------------------,

 The best I could find on this problem is this knowledgebase article, which is unhelpful since we don't have a proxy.

I've added both *.sophos.com and *.sophosupd.com to the trusted sites list, and going to http://dci.sophosupd.com/ returns the message it works - authed. Additionally, I can navigate sophos.com from the browser without issue, but cannot access either https://cloud.sophos.com or https://dzr-mcs-amzn-us-west-2-fa88.upe.p.hmr.sophos.com/sophos/management/ep from IE. I can, however, get to those sites form Chrome, though the latter link returns net::err_cert_authority_invalid.

It's a windows 2003 SP2 server with IE 8, and fully up to date. I would wonder if that was the issue, but I have others like that with it running.

I'm stumped and could use any help.

Thanks