Thanks for your post.
Unfortunately we do not have enough experience about ServerXMLHTTP. Generally “automation server can’t create object” refer that it was unable to create the ServerXMLHTTP. Please make sure, you have the Microsoft XML Parser (MSXML) version 3.0 or later installed.
Please note, any pop-up windows do not automatically inherit the authentication from the parent window. It also could be security issues with the ActiveX which don’t appear in the main IE browswer.
Hope this helps.