In 14.10 when I pressed a volume key on my keyboard, the volume value would show in a popup in the top right corner of the screen.
The volume keys still work (I can hear the "pop" sound) but the notification popup does not show anymore since 15.04. Is it something normal for 15.04? How can I enable it back?
I still have notifications but one strange thing I noticed is that when the notification popup appears, for example when a new mail is received in Thunderbird, or by manually sending a notification with "notify-send" from a terminal, the look&feel of the popup is not the same at all than with 14.10. The background is now light gray instead of being dark brown/gray.