Odd Pics on my screensaver

I put pics that I like in a folder and use that as a screensaver folder. For some reason I see screensaver pics that are not in that folder or anywhere else on my emac 800 running 10.5. I've looked thru all 316 pics and even looked at the folder with Terminal with "ls -al" and there's no hidden pics in the folder, but they come up on my screensaver, And they're pics that I would never save (pics of people I've never seen or care to see). What is happening when pics appear from somewhere else than the folder I've picked as the screensaver pics folder?