i don't know where this white line comes from..it's not on the acutal picture image...nor on the file. It just randomly pops up sometimes.. and is very annoying??? Anyone got any clues???
looks like a giant space tampon jk I don't know maybe check one of your layers, or edit it out with the clone stamp where it seems to be since you said you can't see it usually.
That's a Finder screenshot, so it's not anything in PhotoShop. Does it always show up in the same place? "Random" could mean either time or space. It could be something with the screen. Next time it shows up, change the screen rez to something like 800x600 and see is it is still there. Could be bad pixels.