SD 16GB Card No Longer Recognized As Such

I have two identical SD 16 GB cards in use for 6 months or so with no problems.  Recently formatted one on a VISTA machine.  Now no longer recognized as an SD card.  Works well as a high capacity flash drive.  Any way to restore the card as a 16GB SD card?

NOTE: All SanDisk memory cards come pre-formatted. SanDisk USB flash drives doesn’t need to be formatted out of the box. If re-formatting is needed, follow the steps below.

WARNING:  Backup all your data before formatting. 

Formatting your memory card, flash drive or device:
1. Double-click My Computer,  or Computer (for Vista) 
2. Right-click the drive letter associated with your memory card, flash drive or device, then select Format  
(in the sample image below, we right-clicked on H:)
WARNING:  Make sure you select the correct drive letter. 

3. Select a File system type.
NOTE: Select FAT32 for 4GB or higher capacities. FAT for 2GB or lower capacities

4. Click Start.

Memory card info and old cameras
Many previous old cameras and portable devices do not work if the card is formatted as FAT32 or NTFS file system. One of the following errors may occur if your device does not support FAT32 or NTFS: 
 - Error message asking to re-format the flash card.
 - Error message that the flash card is not formatted.
 - Error message indicating that the card is anomalous.

To resolve the above error, backup your data and reformat your memory card in FAT file system.
If the error persists, re-format the memory card using your camera or portable device.

Hope this one will help you out.

Tried formatting on various computers and operating systems including Vista and Windows 7.  No luck.  Stuck the card back in the camera and once again got a “Check Card” message.  Decided to go ahead and try to format the card using the camera.  It worked!!  The card is again recognized as an SD Cam card by the camera as well as the various computers.  Appreciate your reply.  Thanks.