DAW stops when I use soundcard control software?

Ok, so this is new to me: When I record or playback, if i switch windows to RME Totalmix, rec/playback stops and resumes when I choose cubase project window as active window. This has not happened before, I regularly use Totalmix to tweak headphone mixes when recording bands, so my guess is that this is now happening because I use VSTi (XLN drums)? Yes, I’m completely new to VSTi:s…
I don’t have the time to test this at the moment, so I 'm hoping someone can tell me wether I’m right or not?

Your VST Drums has nothing to do with it. You may need to uncheck Release Audio Driver in the background in the Cubase Preferences

Of course, you are right! I changed that to be able to play back exported autio without quitting cubase.
Thank’s shanabit!