ii gtk2-engines-oxygen:amd64 1.3.1-0ubuntu1 amd64 Oxygen widget theme for GTK+-based applications
ii gtk3-engines-oxygen:amd64 1.1.1-0ubuntu1 amd64 Oxygen widget theme for GTK3-based applications
maybe you can try the kubuntu iso.
i install from that.
and i have try in the livecd.
it will cause that problem too.
ii gtk2-engines- oxygen: amd64 1.3.1-0ubuntu1 amd64 Oxygen widget theme for GTK+-based applications oxygen: amd64 1.1.1-0ubuntu1 amd64 Oxygen widget theme for GTK3-based applications
ii gtk3-engines-
maybe you can try the kubuntu iso.
i install from that.
and i have try in the livecd.
it will cause that problem too.