iPhoto6 does not recognize photos edited in Photoshop 3!

My iPhoto6 software does not recognize photos edited in Photoshop 3!!!!! Please don't tell me to save them in jpeg, instead of photoshop. It doesn't matter. Fortunately, I saved Photoshop2, so I went back to it and did my editing (type layering, etc.) and my photos were accepted by iPhoto6 as a jpeg. What is going on??? Am I the only one, who has encountered this? So, Photoshop 3 is better how?