Memory Card Issue? (Canon SX30 IS)

Hi everyone, my sister has a Canon SX30 IS and while on vacation she was going through her photos (backwards, ie newest to oldest) when she came across an unidentified image. She scrolled past this image to find that about 200 photos had mysteriously gone missing from her 4GB SD card. I'm simply assuming that the card is corrupt...
Has this happened to anybody else?
Are there any ways of getting those photos back?
Thanks in advance everyone.

Sounds like it could be a bad card. She'll need a card reader, but there are a number of file recovery utilities that people have used in this thread.

It happened to me about one month ago on my SX20. I couldn't see the pictures on the card when in the camera. I installed the card in my card reader and all the pictures were there. Since then, it didn't happen but I found that to be very weird also.

**Edit**
I originaly thought that CHDK might be the culprit, so could you tell me if your sister has CHDK installed on her SX30?

Hopefully, she can get the shots back on her computer.
Afterwards, have her format the card in the camera before using it again (or replace the card).

I've seen the "Unrecognized Format" image on my SX30, but only after I've modified the photo using an outside editor, then plugged it back into the camera. (cropping, brightness correction, etc.)

Luster wrote in post #11567638
I've seen the "Unrecognized Format" image on my SX30, but only after I've modified the photo using an outside editor, then plugged it back into the camera. (cropping, brightness correction, etc.)

The same thing has happened to my wifes Sony cybershot. When she rotates an image using Windows picture viewer and then puts the card back in the camera, all she can see is garbage data. No discernible image atall for any image she has rotated.

Thanks for the input everyone. Just to clarify, the card had not been removed from the camera between the times of everything being ok and the disappearance of the photos. So it wasn't due to an image altercation by an external editor. Also, only about 200 of her 600-something images were "erased" for lack of a better word, so I have no idea what's going on. I also haven't been home yet to plug the card into my computer. I'll do that tomorrow and then post here again.

cokethenwpepsi wrote in post #11568181
Thanks for the input everyone. Just to clarify, the card had not been removed from the camera between the times of everything being ok and the disappearance of the photos. So it wasn't due to an image altercation by an external editor. Also, only about 200 of her 600-something images were "erased" for lack of a better word, so I have no idea what's going on. I also haven't been home yet to plug the card into my computer. I'll do that tomorrow and then post here again.

Yes, please let us know if the images show up on your computer. thanks!

also, once you've noticed images are missing, stop using the card immediately. If you continue to take pictures, the damaged or erased image data wouldve been over written and recovery of all missing images might not be possible.

I've used several of the softwares recommended in that thread posted by Jon...
Only 9 images have been successfully recovered. This does not look too promising.
Luckily it was only vacation photos rather than something extremely important (although still unfortunate).
Also lucky that I had brought my camera as well so we are not without photos.
But as for her, it looks like we're just going to accept it as an unlucky inconvenience and move on.