I have a new issue since installing Windows 8, and I need help.

I am a member of a stock photography site where I periodically upload images for sale.
Since I installed Windows 8, ALL my vertical images appear horizontal on that website after I upload them.
In my computer, rotation is displayed correctly, both in Windows explorer and in my several photo software programs I use.

However, during this upload process, rotation information is lost, and vertical images always end up horizontal oriented after the upload, and this is a big problem for me.

Problem did NOT exist in Windows 7, just appeared after windows 8 upgrade.

Any help will be much appreciated?
Thank you