Photoshop :: Is Rotating My Photos

Photoshop (I use CS1) is taking photos that have been saved vertically and opening them horizontally. If I rotate the photo back to vertical and save it again and then try to re-open it, it's horizontal again. Opening these same files with other image viewers and browsers shows that they are clearly vertical, yet PS continues to open them horizontally. I've been using Photoshop for years and never had this problem until the past couple of days, so I'm totally baffled. It's not like I just installed it. It's been working fine and never had this problem before yesterday. It also isn't doing it on older photos that I've saved, it's only new photos that I've saved in the past couple of days, so obviously it's doing something when I'm saving them that's causing it to rotate them automatically when re-opened.

When I try to open these exact same photos on my other comuter that has an older version of PS (7.0) this problem doesn't occur -- the photos are vertical, just as they should be.