One question I would ask is are you sure the lens cover is opening all the way? I had a similar line on my PowerShot A series camera. The lens did not fully open on the one side due to some fine particles of dirt in the lens mechanism. I used some compressed air for electronics and cleaned that dirt out of the mechanism, which resolved the issue.
However, if you are having focus issues, it sounds like there could be something like a hair stuck in the barrel of the lens, but for it to show a line on the images, that could be near the filter that protects the image sensor or inside the lens. I would think the camera needs to be opened to inspect the sensor as well as the lens. If the hair is indeed inside the lens, between the glass elements, that would be an expensive repair as the lens would need to be aligned after it was cleaned. If it's at the sensor, it should be a less expensive repair. Are you using the macro mode when you are shooting the close ups? Maybe you're getting a little too close. I tried zooming in for close up shots, but needed to use closeup filters because I was getting too close. Plus, I have accidently left the macro mode on when I didn't need it, and of course the camera would not focus properly. Just asking.
Steve M.
