Hi Breeze,
A few things come to mind. Usually when your move from one device to the other, the best thing to do is use our free Time Master Central app to "Backup" the entire system and "Restore" it to the new device. On iOS 4 devices, you can also use the "File Sharing - Documents" option to Backup & Restore. That would ensure that all the files and settings would be transferred to the new device, mirroring the old device.
That being said, my best guess is that you have a "Rate" setup incorrectly somewhere. The Rates are determined in the following order and used when you create a new entry: Global -> Client -> Project -> Task -> Custom. Since you say that you verified that the Client has a correct rate, my best guess is that you also are using Projects and/or Tasks too and one or the other has a zero in it. You will need to verify that you have not set the rate to 0 (zero) in either the Project or Task. If they do, just tap on the little grey "X" to remove the rate and tap Save.
Please let us know if this helps?
Cheers,
Adam.