said by Zergle :So that I understand it: did the OP have the problem because he had a setting for his voip.ms account that blocked calls that cost more than xx cents per minute?
The way it stands now, it sounds like there was a problem with voip.ms and that it could somehow not connect to that French number or maybe to any French number.
The issue wasn't because of cost restrictions on international calls on the affected account. The account was configured to allow international calls priced at up to 50 cents/minutes.
In a voip.ms support ticket, two techs said the problem was that routing to French DIDs having a 337 prefix could not be done from voip.ms because such DIDs were unreachable "International Premium" destinations. They provided no further explanation of what that meant. However, Martin and Peter at voip.ms are working with their support staff to fix this. I'll post an update if the issue is resolved.