Sometimes, in Photoshop, my rulers are off centre:
In this case I have the Move Tool selected, I've just placed the image of the pin. It always seems to go away after a while, but I haven't worked out what causes the rulers to snap back to where they should be ([0,0] at top left corner). Changing layers/tools doesn't, nor does opening the rulers preferences panel.
Why does this happen?
How can I revert the rulers back when it does?