Latest info from JPL:
SPIRIT
UPDATE: -
Jan 22, 2004, 10:35 am PST
The Mars Exploration
Rover Spirit radioed a beep Thursday morning confirming that it had
received a transmission from Earth. Still, it has not returned any
data since early Wednesday. Flight-team engineers for NASA's Mars
Exploration Rover Project are working to diagnose the cause of
communications difficulties.
-- Joe