For some peculiar reason, my desktop pictures do NOT change / rotate on my secondary display. I have a MacBook Pro 15" (Late 2007) running Snow Leopard 10.6.2 and I have dual displays. My primary display (the MBP screen) DOES change / rotate picture every minute, but I want my secondary display to do the same. It seems that restarting does fix it, but only temporarily. I think it might have to do with plugging/unplugging the secondary display and sometimes if it's working, I disconnect and reconnect the monitor and then the pictures stop rotating. All my desktop picture settings are correct in System Preferences. I tried unchecking then rechecking the "Change picture:" checkmark, but that doesn't fix anything. I also tried clicking on different folders in the left column of the Pref Pane, then clicking back on my chosen desktop pictures folder. Any help would be greatly appreciated! Thank you!