I hope this is the right forum for this -- I think it's a ML problem because there is another known ML problem that's similar, but I can't be sure about that as it only occurs on one of my two computers (2012 rMBP). I've got my preferences set to randomly circulate through wallpapers within a particular folder every 30 minutes, but ML doesn't save these changes. At first I thought it was something akin to the problem others have mentioned, wherein their wallpaper resets to default when they login, but I've found this problem is not limited to restarting or even waking from sleep; it's just as likely to reset itself within a single active session. I thought it might be a problem with ML accessing the folder I specified, so I tried removing the folder path from the preferences sidebar and then putting it up again, and also making a completely new folder and trying to circulate from that one instead, but the same issue occurred in both cases. Has anyone else had this problem? Any fixes for it?