Just to be absolutely clear:
When you now create a brand new document with pixel aspect ratio correction off and with square pixels in the create document dialogue are you still seeing the aspect ratio incorrectly?
If so I would reset preferences. Go to Preferences >General>Reset Preferences on Quit and then click OK. You will then need to close and restart Photoshop.
If you are only seeing this on existing documents then turn off the aspect ratio correction and use image size (with resample) to correct the ratio and resave the document.
Problem solved. Thank you so very much, such a relief. For whatever reason the pixel aspect ratio was set to wide screen as opposed to square as I'm accustomed to.
I can't thank you enough, I'm such a visual person, I learn with my eyes.. I truly appreciate your assistance with this issue! The pictures were really useful.. you're a life saver
All the Best!