Receiving message ''card door open''

The problem you are describing is a problem with the sensor on the card cvover door. It seems to have failed and needs to be replaced.

Based on what you report the camera would need to be serviced. Regretfully all parts, accessories and repair service have been discontinued due to the age of the camera.
You may refer to the yellow pages for local camera repair centers who maybe able to offer parts and service on the camera.
As a loyal Olympus customer, the Customer Service Department is also available to discuss other options available to you.
They can be reached Monday through Friday, 8:30 AM until 7:00PM East Coast time, at: 1(800)622-6372 option 2 and then option 3.

if this is on the C370 its likely the bit of plastic in the battery door that pushes the button in has snapped if you look near the memory card there is a small "catch" with a button inside when you slide the door closed in the door there is a lip that slides down and pushes the button shut hope this helps