Camera not working with memory card inserted

HiI have an Olympus CAMEDIA C-40 ZOOM camera that’s about 4 years old.  It uses a large memory card which is no longer available at most retail outlets.  The camera suddenly stopped working (lens wont pop out) when the card is inserted.  When I remove the card the camera will switch on but is useless because it has no memory.  I can read the memory ok in my PC but clearly the camera doesn’t like it.  I haven’t been able to test the camera out with another card because of the lack of availability of this card.  Can anyone suggest what the problem might be?  Thanks.