SOME APPEAR AND SOME DON'T

Dreamwaver CS3

Bear with me.

I'm trying to place a png or jpeg image in a table. I go and set up a "image
place holder" title it with the correct name of the image, I go back
"double-click" inside the icon and "Select image box appears", I find the file
and "double-click" it imports into the page??? No image?

Some images come in and some don't, can someone tell me why that is happening?
And how I can fix it?

Thanks