I have 2 of these as part of our computer network, and I too have experience these error messages, what they mean is that there is no power to the main board from the CMOS battery. make sure the new battery is not discharged and that the terminals and battery are clean from finger grease / dirt. I used electrical tape to secure the terminals to the battery after cutting the shrink wrap off the Original. Then make sure that the connector is pushed home firmly.
If this still doesnt work continueity test the connection wires. If none of then works then perhaps you have a mainboard fault.
Göran
October 2005