It looks that the sequence of frames displayed at the screen is mixed up. The display goes back say ¼ a second and that gives a very strange effect. You type a letter, that letter is erased afterwards and reappears after ¼ of a second. See the ATTACHED video. You see the same type of going back a number of frames in e.g. YouTube videos, which gives a jittery effect.
See also the Conky graphs going sometimes backward in both videos :)
The problem only occurs if I have 3D acceleration enabled in Virtualbox and it occurred with both Ubuntu 16.04 and 17.10 hosts. It only occurs at Ubuntu 16.04 guests, the problem does not occur in Ubuntu 17.10 nor in other Linux distros including Ubuntu Mate and Xubuntu. I use Virtualbox 5.2.6 with Guest Additions 5.2.7 as recommended by Oracle on their website.
ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xorg 1:7.7+13ubuntu3
ProcVersionSignature: Ubuntu 4.13.0-36.40~16.04.1-generic 4.13.13
Uname: Linux 4.13.0-36-generic x86_64
.tmp.unity_support_test.0:
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Thu Feb 22 23:35:36 2018
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard: InnoTek Systemberatung GmbH VirtualBox Graphics Adapter [80ee:beef] (prog-if 00 [VGA controller])
InstallationDate: Installed on 2017-03-29 (330 days ago)
InstallationMedia: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215.2)
Lsusb:
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 80ee:0021 VirtualBox USB Tablet
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: innotek GmbH VirtualBox
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-36-generic root=UUID=82019235-3f7b-4b99-b622-d6bb790566d5 ro quiet splash zswap.enabled=1
Renderer: Software
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/01/2006
dmi.bios.vendor: innotek GmbH
dmi.bios.version: VirtualBox
dmi.board.name: VirtualBox
dmi.board.vendor: Oracle Corporation
dmi.board.version: 1.2
dmi.chassis.type: 1
dmi.chassis.vendor: Oracle Corporation
dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:rvnOracleCorporation:rnVirtualBox:rvr1.2:cvnOracleCorporation:ct1:cvr:
dmi.product.family: Virtual Machine
dmi.product.name: VirtualBox
dmi.product.version: 1.2
dmi.sys.vendor: innotek GmbH
version.compiz: compiz 1:0.9.12.2+16.04.20160823-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.83-1~16.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 17.2.8-0ubuntu0~16.04.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 17.2.8-0ubuntu0~16.04.1
version.xserver-xorg-core: xserver-xorg-core N/A
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati N/A
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A
xserver.bootTime: Thu Feb 22 23:13:23 2018
xserver.configfile: default
xserver.errors:
Failed to load module "vboxvideo" (module does not exist, 0)
Failed to load module "vboxvideo" (module does not exist, 0)
modeset(0): glamor initialization failed
AIGLX: reverting to software rendering
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.19.5-0ubuntu2~16.04.1
xserver.video_driver: modeset
Another video with an audio player and a progress bar and counter sometimes going backwards