Hmmm, When I was trying with IE7, it never worked, I tried with the firewall disabled to no avail. I had a feeling that either Calibre or Stanza is using some form of HTML Web in the communication or formatting system, so I tried Apple Safari and it worked straight away. I then Put Firefox on and the same thing, worked. Since Calibre seems to be Linux based and Stanza Apple I'm guessing that Windows users are on their own to a degree.
If firefox failed for you, try Apple safari. Oh just a thought, your Antivirus, Firewall program may still be the culprit. I use Windows Live Care and i'm sure somehow it is responsible for 50% of my problems, but I don't know enough to justify that statement, just a feeling.

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