Olympus camera (sp-510uz) -took photos- but reads no image...?

Question: Olympus camera (sp-510uz) -took photos- but reads no image!.!.!.!?

i took lots of photos on my olpmpus camera and when i went to download them all it says no image to download!.!. and now on the camera it says 'no image'!.!. i know it took all the photos because i was looking at them in the car on the way home!.
what happened to them!?!? are they stored somewhere on my camera!?!?
also pictures that were taken 8 months ago are showing up on my camera again!.!.!. after i have downloaded an deleted them!!?!Www@QuestionHome@Com

Best Answer - Chosen by Asker:

You may have inadvertently changed the media card in your camera between the time you last looked at the pictures and replaced it with an old one!. Or you might have removed the card altogether and are relying on the images that remain in the resident in-camera memory!.Www@QuestionHome@Com