PS resizing problem

Hello everyone,
I have a little problem whit resizing pictures in photoshop 7. I tried the memories, but with no luck.
When I resize a picture, some kind of border appears, something semi-transparant, I don't know.
I frist cropped the pictures, then I resize the canvas so it's a perfect square, and then I resize the image to 100x100 px.

Here's what I get:

I don't know if it's clear for you where the border is?

Then when I try to stroke the whole layer it only strokes this:

The left side is the side where I resized the canvas.

How can I resize pictures without having that strange border?
I don't understand, I never had this problem before :-s Probably there is a logic solution for this which I haven't seen?
Thank you!

Edit: Problem solved, thank you!