Firewall blocking .acsm files using Adobe Digital Editions

[#1]

I have authorised the computer and am able to read epub and pdf files.

When I try to open a document with the .acsm extension I get the following error message:

Connection Error Detected

Digital Editions could not connect to the fulfillment server. Please make sure you are connected to the Internet.

Any help with this would be much appreciated

[#2]

Has you try to add ADE as sure problem in your firewall?