David,
I don't usually deal with scanned JPEGs however...
In a contact sheet I rotate an image (JPEG file). If I then add a star rating, the rating is applied but the picture returns to its original un-rotated state.
By design? Or my failure?
It's a deficiency in scanned images. The scanner doesn't put in an Orientation EXIF tag and PM won't manufacture one and insert it. So while it appears to be rotated temporarily, the file itself does not have the data stored in it persistently thus when you make an additional change and the file is re-read the orientation reverts to "unrotated".
So while PM could maintain that information in memory longer, it would still revert to un-rotated in any other software you might use, and in PM once you quit it and reopen it.
-Kirk
