xvnc4viewer F8 not working in Xubuntu 16.04

[rewound]

Hardware setup unchanged: Acer Aspire One

Old:
Peppermint 3 (Note: Peppermint 4 was based on the Ubuntu 13.04)
Kernel 3.2.0-48-generic

xvnc4viewer version 4.1.1+xorg4.3.0-37ubuntu4
The F8 key is used to change settings including getting out of fullscreen mode; a pop up menu appears and works.

New:
Xubuntu 16.04
Kernel uname -a
Linux mvac16 4.4.0-22-generic #39-Ubuntu SMP Thu May 5 16:52:40 UTC 2016 i686 i686 i686 GNU/Linux

xvnc4viewer version 4.1.1+xorg4.3.0-37.3ubuntu2
The F8 key is used to change settings including getting out of fullscreen mode.
Once in this mode the user is stuck in the session because F8 no longer does anything.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:16.04.14
ProcVersionSignature: Ubuntu 4.4.0-22.39-generic 4.4.8
Uname: Linux 4.4.0-22-generic i686
ApportVersion: 2.20.1-0ubuntu2
Architecture: i386
CrashDB: ubuntu
CurrentDesktop: XFCE
Date: Mon May 9 10:40:04 2016
InstallationDate: Installed on 2016-05-07 (2 days ago)
InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Release i386 (20160420.1)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
Symptom: dist-upgrade
UpgradeStatus: No upgrade log present (probably fresh install)