Hmm, that's very strange, this is the first time I've ever seen this issue. Are you having any problems with other information not add/saving in DomainMOD, or is it just the fees?
Can you do the following and then see if the fees update at all:
- Click on Settings -> User Profile, and then change to a completely random currency.
- Click on Maintenance -> Update Conversion Rates. After a short period of time you should receive a message that says, "Conversion Rates updated".
Now go into your registrars again and see if the fees are still all set to 0.