dvd's not unmounting

English Install/Boot/Login
1

I’ve been having problems with k3b permissions so I tried growisofs to see some output and it was a problem with un-mounting dvd. so I unmounted the dvd that was previously in my dvd writer drive from the new location /run/media/$USER/ and then k3b worked fine.

So to make sure it wasn’t a fluke I reinserted a dvd, had it mount. Then I took the dvd out. Still mounted.
Any clue what the problem is?

2

a short term fix was to make a shortcut (system settings->keyboard->shortcuts in gnome 3) and make F12

gnomesu umount /dev/sr0

…which is fine now that I know what to do, but never had this problem before.