Sure you did not lock the card? The little notch should be in the up position as in the picture. Then the manual says you can use SD cards up to 32 Gbyte, but I can't find anything about the cameras compatibility with SDHC cards. So try the camera with a SD card. The used to make SD cards up to 4 Gbyte, but today, even 1 Gbyte cards are SDHC.
1- check Lock
2- Use SD card to see if your camera works with that.
See a 4GB card, only SD, but not for sale anymore.