Found this Panasonic post in the Samsung section!
If it moves just a tiny bit when the door opens and then stops, that's normal.
If it keeps running when the door is open, that's usually due to a bad door switch or broken / loose door switch mount.
If you or a friend decide to look into it, we have critical safety information, info on door switch diagnosis and replacement, and
disassembly information at our site, linked here on Fixya:
http://tinyurl.com/yzjozk
Any Panasonic parts not available locally can be had here:
http://www.pasc.panasonic.com/epartr
We appreciate your thoughtful rating of our answer.