Is the card too big? Some old cameras -- and an ist-D is very old in digital camera terms -- are limited as to what capacity chips they can use. Check your manual or Google it. Also, it's not unheard of for a chip to be defective right out of the box. Try it in another device to ensure that it's not a defect.
Sounds like your shutter is stuck. Given that the camera is only worth about $100 -- or even less -- it's probably not worth sending in for repair. You can buy a good used "upgrade" like the K200 or even the K-50 for about what a shutter replacement would cost.
On an SDHC card, there is a micro-switch on the left hand side, which sets the card as locked or unlocked. Move this to the unlocked position. The card may also need to be formatted in the camera.
Tony your camera is now over 30 years old. THe fact that this is all that is wrong with it is a blessing. But why are you still shooting film? There is nothing you can do on film that can not be achieved on digital.