Count me in. I'm using an iPhone 5 and since upgrading to iOS 7.0.3 I encountered this bug.
I noticed some strange circumstances:
I use a 4 digit password to open up the phone. My initial setting is that it should auto lock after 5 minutes and that the pass need to be entered after 5 minutes as well. Using this the camera instantly forget the "HDR on" setting when accessing the camera from the lock screen (after 5 minutes or more).
Setting the time to 1 minute or instant for using the pass to open the phone it remembers the "on" setting for a little while (up to 20 minutes, but not 30) and then turns it to "off".
Also when opening the camera from either the lock screen or the app desktop after a longer while the yellow letter indicating "HDR on" is visible for a half second or so before turning itself to "HDR off" in white letters.
Very frustrating since I use the camera and HDR several times on a daily basis.
I was I'm contact with the Swedish Apple support on Thursday October 24 and they had not heard about this. I was told to do more experiments (turning off the HDR setting, take a photo, turn it on again, reboot, reset settings) and get back to them using my case number that was supposed to be sent out, but I never got it. Their suggestions didn't work either, the bug remains.