>>Hi Naomi
>>
>>>It is definitely a TeamViewer application. This time it did reset the theme back.
>>
>>We are using Teamviewer for years and never had a problem with it.
>>We´ve been testing it on Win XP, Win7, Server 2008 and Mac OS.
>>Must me something very special with your setup.
>>
>>Make sure you are running the newest version.
>>
>>
>>Chris
>
>The version I have is 5.0.572
>
>When someone connects to my machine, my background becomes black. It may or may not restore back correctly once I close it.

Did you check the Settings in Optionsmenu?