Ubuntu – Ubuntu volume control slider moves strangely

Not sure if this will help too much, but I've found that if you go through the system testing program (I think that's what it's called, anyways it has a thumbnail of a monitor with a green image, just search for it under installed programs) it will sometimes fix things like that. If you want you can just skip all the tests except for the media key tests, but I find that the other tests are still helpful. You can also try googling for changing fn key values, I know a lot of keyboards have the option to reverse the F keys and the funtion buttons, so that for F1 you would need to press Fn + F1 for example, and the media key that would normally require Fn would do it without it. Hope I helped you a little bit at least.

I just got the D3 today and had this exact same problem. Check out the top answer on this thread. For me, these instructions worked:

There are a few variables which control how PulseAudio controls the volume. You can either edit /etc/pulse/default.pa (you'll have to be root to do that) to change the behavior for all users, or copy that file to ~/.pulse/default.pa and then edit that file, to change behavior for the current user only.

Open the file mentioned above. Find the row saying load-module module-udev-detect and change it to:

load-module module-udev-detect ignore_dB=1

To try your changes, restart PulseAudio with the following command:

killall pulseaudio

PulseAudio will then autospawn (restart itself).

I had a block in the config file that looked like this:

### Automatically load driver modules depending on the hardware available
.ifexists module-udev-detect.so
load-module module-udev-detect tsched=0
.else
### Use the static hardware detection module (for systems that lack udev support)
load-module module-detect
.endif

Then I simply added ignore_dB=1 to the end of each load-module line, so that the two lines looked like

load-module module-udev-detect tsched=0 ignore_dB=1
...
load-module module-detect ignore_dB=1