initial installation of package "virtualbox-guest-utils" fails

[LAZA]

I have the problem in virtual machines that the favored virtualbox packages for the guest does not install correct.

- make a new Linux VM
- install Xubuntu (i think, we have the same problem in all the other Ubuntu distros)
- reboot --> get a real small window (800x640?)
- install package Synaptic
- open Synpatic
- go through the options
- - Ubuntu Software all ticked (except sources)
-- other software all ticked (except sources, again)
-- Updates all ticked
-- additional propietary drivers
--> activate Virtualbox-guest
--> accept/do now
--> installation starts (blue bar) but hangs forever

This is cause of NOT reloading the software sources/packages so i got an error that the source is not reachable (or something like that).
After closing the Software-properties window and reloading the packages all works flawless.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: software-properties-gtk 0.92.37.1
ProcVersionSignature: Ubuntu 3.13.0-32.56-generic 3.13.11.4
Uname: Linux 3.13.0-32-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
Date: Wed Jul 16 14:43:49 2014
InstallationDate: Installed on 2014-03-16 (121 days ago)
InstallationMedia: Xubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140225)
PackageArchitecture: all
SourcePackage: software-properties
UpgradeStatus: No upgrade log present (probably fresh install)