Why can't I delete individual pictures in iPhoto?

DanPage,

When you open iPhoto, click on Photos, select a photo, it should be outlined with a yellow border. Then click COMMAND delete, click DELETE PHOT (you can also hold down command and select multiple photos)

It will send it to trash in iPhoto, you can then select the photos in the trash (you can also do a COMMAND A to select all in the trash)and they will outline then SHIFT+COMMAND+DELETE, and click on do you want to delete X photos permanently, click OK then they should be sent to your trash, empty trash securely(SHIFT+COMMAND+DELETE) and they should be forever gone.

this is using iPhoto 9.2.3

Hope this helps