VirtualBox on Mac os x - Can not find com service

Context

Mac Mini Server edition, 16 GB ram, ssd 250GB + hdd 750GB
Mac OS X server
Oracle VirtualBox
Changed (decent word for testing if something would fail) with the Mac OS X server settings, in particular the hostname.

Symptoms

Trying to start the admin screen of VirtualBox fails and gives an error telling that the tool could not connect to the COM service or the VirtualBox com services.
In the details of the error you will find something link NS_ERROR_FAILURE (0x80004005)

Explain

Do not know what is going wrong, but something is smuthering up the file and directory permissions when the hostname is changed and/or Mac OS X server services are recreated and/or restarted

Solution

Go to disk utility (Utilities > Disk Utility)
Select the main disk of the computer on the left pane
Select the first aid tab (the default one)
Click on the button to "Repair the disk permissions"
In the log file you'll see things that seem not to interfear with VBox ... at first ... but looking deeper in the stack ... 

Hope this solves your problem too ... 

References

CAlso : Apple Forum post