Two things I can think of:
1. You might be using non square pixels if you are using CS. To check, go to "Image->Pixel Aspect Ratio" and make sure "square" is checked.
2. I used to (a LONG time ago) have my monitor set at 1280×1024 resolution, which is not a standard 4×3 ratio, and the image on my monitor always seemed stretched, because it would still try and fill my 4:3 screen. Make sure your computer resolution is set to something that has a ratio of 4:3. (i.e., 1024×768, 1280×960, 1600×1200, etc…)
also you could have the monitor settings (on the monitor itself) set to be stretched.
in photoshop, pull up your rulers – does the horizontal rulers match the vertical rulers? if you make a square, does it look square on screen?
As far as 72 vs. 96 vs. 1000 dpi or any other setting goes, that has no effect upon how the image is displayed on your monitor unless you select the View > Print Size option. Only then does the ppi get factored in, in which case the resolution is divided into the actual linear pixel dimensions to obtain a scaling of the image that needs to be applied, thus rendering it at approximately the size it would appear in print. Even then, the resolution of your monitor is a factor. That is, 1 inch onscreen is rarely measured as 1 inch with a ruler held to the screen.
Daryl
What do the pixel dimensions of you image look like? This is the actual aspect ratio. How does that compare?
My money’s on Jonathan’s #2 suggestion.
Thanks for the help everyone. As it turns out it was a little from column A and a little from column B. I had a non 4:3 aspect ration on the monitor setting. After that was changed I opened Photoshop and pulled up the rulers. Measuring the rulers seemed to be the easiest way to check for squareness. Now that the aspect ratio had changed, the ruler ticks measured much closer to one another but they were not exact. To compensate for this I adjusted the geometry of the monitor until they were exact. Now images look right.
Needless to say, I need to recrop a couple of images.
Again thanks to all who replied.