Distro: ArchLinux. I upgraded to XFCE 4.8.0 and opted to migrate the old config. 1. Hovering over the xfce4-mixer panel icon used to display a tooltip with a percentage number for the master volume. After the upgrade to XFCE 4.8.0 it no longer does. 2. Hovering over the xfce4-mixer panel icon and using the mouse wheel used to both: a) change the master volume b) change the aspect of the plugin icon in sync with the mouse wheel so as to give visual feedback for the master volume going up/down. After the upgrade to XFCE 4.8.0 it only does b). The master volume remains unchanged.
*** This bug has been marked as a duplicate of bug 7125 ***