Although I am able to format my 8GB SanDisk SD Card, upon ejecting the card and re-inserting it into the SD card-reader the computer asks me to re-format the card again. This has happened with about 25 SD cards (some different brands). Any suggestions?
i think this issue is related to the card reader that you are using. in that case try inserting the cards with a different reader or pc to see if its related to this hardware and not to the cards.
other possibility is that the cards are defective and needs to be replaced, this can happen also.
Try formatting it using using the SD card formatter.