Dolby Cockpit Surround

I am having problems with the sound config with Dolby Cockpit Sounds. I was running Dolby Cockpit Sounds without any problem with an 2.1 speaker system via my onboard soundcard. To make use of the dolby sounds I additionaly installed a 5.1 soundcard and a 5.1 speaker system. I now have 2 soundsystems in my HomeCockpit: Soundblaster 5.1 > for Engine Sounds Realtek Onboard Soundcard 2.1 > for Cockpit sounds Both soundcards work in parallel. That's not the problem. My problem is, that I can not assign different sounds to different speakers via the Dolby Cockpit program. I change the settings and click apply. On next start up, no speaker is selected. Only the "all speakers" setting is working. I suspect, that Dolby Cockpit does not accept my Soundblaster card correctly. According to the manual I should select the desired soundcard at the bottom of the screen. Doing this, it tells me to restart to change the settings. But it doesn't change anything. The two soundcards are displayed the same way. And to me, it looks like the 2.1 Realtek soundcard is still the active one. See attached screenshot: Can anyone help? Thanks. Michael