InfoPath Dev

We have users in London (on a different Network). I posted forms to a shared folder on our server in NY, but some forms the Londoners are unable to access.  They receive the following message:

The form cannot be opened because it requires domain permission level and it currently has restricted permission. To fix this problem, open the form from the location it was published to.

What does this mean?

Hi:

Generally, it means the form was published with an incorrect security level. You can modify the security level under Tools / Form Options / Security. Since the error recommends domain permission, set the level to domain and republish the form to the location your user is going to access it from.