Originally Posted by AaronM

The pic file itself holds the orientation info and programs like PS or ACDSee read that part of those files. Rather than trying to explain this, I will put it to you this way:

Stop opening the raw photos in your browser. You're not going to load them to your server like that anyway so who cares how your browser handles them?

Edit your pics, watermark them, etc, and when you save them, they will be in the right direction assuming you used a program that reads the full EXIF info.