I was pretty excited to hear Android 4.2 brings lock screen widgets. But after updating my Nexus 7 tablet, I'm not able to do that: I just have a clock widget that I can remove (it reappears after sleep/wake), but I can't add any widgets in any way. At first I was able to swipe right and I got a "+" where I presumably could add them, but now that's gone.
Could it be because I have a corporate (i.e. exchange) account configured and because that forces me to have a password? Or is it some glitch? I have tried rebooting it.