Lately I've been having an issue while editing in PS 6. While working on one part of an image, a thin line of colored pixels will appear. They can appear almost anywhere on the image, regardless of where I'm working. Sometimes they will cross the entire image. Always horizontally. The colors can be magenta, green, red, but the line of them is a consistent color. A magenta line, a green line, etc. At first I thought it was a display artifact, but they are being added to the image. I can erase them with the eraser tool, so they are actually becoming part of the image. I can find no pattern to when it happens, tool being used, anything. They just appear.
I have 16 gb of ram and I'm using 2 SSDs as scratch disks, so I don't think it's a lack of memory.