Help with pictures not appearing in iPhoto

I have used an SD card to import photos to iPhoto. The photos said they all imported; however, none of the pictures are appearing anywhere in iPhoto (not in last import, not in last 12 months, not in any events, not anywhere). When I tried to import them again (thinking they just hadn't imported), it said that all the pictures were duplicates and were already in iPhoto. Then, when I went into the Faces section, it asked me about pictures that we in the back of pictures that isn't showing up. So I know they are in iPhoto somehwere, but they just aren't showing up anywhere that i can see them or edit them. I tried unhiding pictures, but had not luck finding them even then.

Help!

Thanks