I would first like to thank you for developing ploticus, this tool is invaluable when analyzing data!
I had discovered something very strange with my data: when changing file into pathname all of a sudden my data changed. I was surprised to notice this, and found my bug after a while. I had cloned getdata which used file, and used it in a getdata where I used pathname.
A very strange and dangerous configuration, I can assure you. Perhaps an error message to other users encountering this strange problem would be interesting. I know what to look for next time :-)