More than likely, these are pictures that you are uploading from a mobile phone.
If that is the case, then they to appropriately oriented before the upload. If you're having difficulty figuring out if it's right or not, try turning off auto-screen rotation on your device.
Once the image is correctly oriented, re-save it before uploading.
it only happens when i turn my phone sideways for a wider pic... ill keep playing with it and find a fix... rotation lock seems to have the best effect so far but still not 100%...
I just noticed a similar issue. If I take a pic in landscape mode, it appears just fine on the screen before uploading. After it's uploaded, int rotated