The SmartMedia card should only be removed after the PC Card card is removed from the computer. Having the adapter inserted at any time without a SmartMedia card in it will render the adapter invisible to the computer, and require the user to force-eject the adapter. My laptop, an NEC 6030, runs both Windows NT 4 and Linux. I had to open the Disk Administration utility and manually reassign the card to a different drive letter and reboot. Once I did this it worked fine.
Image sensors are complex devices.
If just one pixel out of several hundred thousand goes bad, the result can be an unusable camera. Dust can't be seen in the dark. On the other hand, if the problem is internal dust and you're feeling brave, you might want to try disassembling the camera and blowing out the dust. This website was made with a Macintosh.