That is very odd it should detect that way.
Let's try using a forced recovery option to get them from the card reader and then you can format the card to get it working.
Download and install recuva from here: Click Here
Once installed put the memory card into the slot and ignore/close the error message.
Click on next and then on pictures and click next again.
Click on media card or ipod and click on next.
Put a check in the enable deep scan box.
Then click on next and if it is able to recover the photos they will show up after the scan.
If this did not work, please come back and let me know what happened when you tried it by clicking on reply to expert so we can continue.
If it did work, please don’t forget to leave a positive rating - it is greatly appreciated.