It was mid 20's here today and I probably wouldn't have even noticed my line today until I zoomed right in to look at the detail on my photos and saw the band
I took 3 images from the street performers and put them on layers above each other and they line up in the same spot each time. I did however record video of a performer before hand and that might have contributed to it. I pixel peeped at images prior to the video and can't find the lin, sometimes I find almost not a line but a concentration of noise line but its so faint I can only see it at 400%.
Just took a image while at home and the camera hasn't been used for some time. Took a picture of interior door and don't see it...Is ther eany adjustment sin photoshop that helps bring them out.
Here are my images with the line. The photos were all at 200 ISO as it was pretty sunny afternoon. at the bottom of the image is the 100% crop of the area in red at top of image.
http://stevenkovickart.com/pentaxforums/elvisline.jpg
It may be also worth to note that most of these posts have been about under expossed photos, where mine are very sunny well lit photos.