When calling the GetValidationReplay method on a login that finished a race, the dedicated server returns error message "Unable to retrieve validation data."
This is a critical error, because Dedimania won't accept online records from TM2 servers unless they're accompanied by a validation replay, as a check against online cheating. xbx, please fix in the next release.
Edit: The same problem occurs with the SaveBestGhostsReplay method. And it's probably related to this bug as well.