Hi,
Thanks for the post.
If our understanding is correct, the credentials are properly invoked in one box. But in your own machine, all credentials are filled in the same field. Is this correct? If so, please go to Start--Run and run the exact command from your machine with the correct credentials. Add each value within double quote and then try invoking it. If it works on one machine, it should also work on others. Also, let us know the IE version in which it worked and the version that you are using. This will help us in identifying the root cause. You can also edit the AutoLogon entry and send us the snapshot of the command configured.
Look forward to hear from you.