Were you doing a second coat of primer? If the first coat wasn't completely dry, attempting to put a second coat on can lift some of the first layer.
Also, soap isn't necessary if you are using water-based paints. You have to rinse the dickens out of them, but no soap. I don't know for sure what residual soap would do to the finish, but it breaks surface tension and might have some bad consequences.
Also, soap isn't necessary if you are using water-based paints. You have to rinse the dickens out of them, but no soap. I don't know for sure what residual soap would do to the finish, but it breaks surface tension and might have some bad consequences.