I think we have the EXACT same problem. I got Vignette Free to test it out since I don't like Camera360. I took a video of the problem and am curious if this is normal, or if its me, or what? BY THE WAY, I don't know why the video uploaded the wrong way, lol, I was actually holding the phone in Normal Mode (not landscape) the whole time ... so if you want, til your head to the left haha.
Check out this video I took from my wifes little LG Vortex on what is happening.