I have been using this plugin on an MU installation and love it. Tonight I noticed the upgrade link and clicked to upgrade automatically. It returned a string of fatal errors and broke (and by broke I mean like all you get is a "Oops! Can't load page" error for the main URI or the admin area) every site including the ones that weren't using the plugin. I tried copying the older version back onto the server--no change. I tried flat-out deleting the plugin thinking it would just auto-deactivate, nope. I did a file backup via my host's control panel and tried again from the main blog. It did upgrade successfully but since the main blog didn't use the plugin there was no error to record in reactivation attempt. Moving on to a blog that does use it--fatal errors everywhere, every blog down. Had to restore from host files again, this time I left it alone. I'm wondering if anyone else experienced this.