Or search all the files related to PS and destroy them, sure you will have your quickbar options erased but that doesn't say you can't do it again, or maybe even save those specific files or logs.
What I would do would be to uninstall, destroy all traces of Planeshift, except the install, then reinstall it and check if it works.
I tried to update a few days ago and it went fine for me, tough that no insurance that it'll go just as swell for you
Peace