I get a memory card error even though it has a card installed

Http://www.usa.canon.com/cusa/support/consumer/digital_cameras/powershot_a_series/powershot_a70#ServiceAndSupport

Issue: Memory card Error
Solution: Try a different memory card and/or Reformat memory card PowerShot A70


Formatting a CF Card You should always format a new CF card or one from which you wish to erase all images and other data.
Please note that formatting a CF card erases all data, including protected images and other file types. Please check the contents of the CF card before formatting it.

1. Turn the power on.
   
   
2. Press the <MENU> button and select I get a memory card error even though it has a - tools_icon.gifploads/images/tools_icon.gif" alt="toolI get a memory card error even though it has a - direction_arrow_lt.gifi" />(Set up)] using or .
   
   
3. Select (Format) using or and press the <SET> button.
   
   
   
   
4. Select [OK] using or and press the <SET>I get a memory card error even though it has a - note_icon_a70.gif/>
   
   
   
   • To cancel formatting instead, select [Cancel] and press the <SET> button.
   • The capacity of the CF card displayed after formatting will be less than the rated capacity of the CF card. This is not a malfunction of the CF card or camera.
   
   
   
5. Press the <MENU> button.

• If the camera does not work properly, the inserted CF card may be malfunctioning. Reformatting the CF card may solve the problem.
• When a non-Canon brand CF card is malfunctioning, reformatting it may solve the problem.
• CF cards formatted in another camera, computer or peripheral device may not operate correctly. When that happens, reformat the CF card with this camera.