Why do my rulers not line up sometimes?
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?
You simply changed the zero origin point.
Here is the movie oh how to fix it.
"You can change the rulersâ€™ zero origin by dragging diagonally down onto the image. The ruler origin also determines the gridâ€™s point of origin. To snap the ruler origin to guidelines or gridlines, choose View > Snap to Guides or View > Snap to Grid, before dragging.
To reset the ruler origin to its default value, double-click the upper left corner (origin) of the rulers."