Maybe a bit late here---the resident geniuses (geniuii?
) seem to have solved this BUT having photos or images displayed on most any message board is dependent on your image size, more importantly its height to width size.
These boards like images that are 800 pixels wide by 600 tall---if your image is taller than wide it will default to that orientation. If cropping an image gives the wider final size that's the main reason.
Sometimes we can't resize or crop an image to that display orientation and it has to be "sideways". Some sites---but not many--do allow a poster to edit their images once its uploaded, generally most do not though.
Hope this helps---and hope I'm NOT in error!