Ok Guys, I think I tried everything but dsound.dll is still not loaded :S
I ran Arma as an Admin, I deleted dsound.dll from everywhere and ran SixUpdater with "beta" option checked and have updated/downloaded the @JayArma2Lib_new mod.
But I still have the missing dll errormsg in the upper right ingame.
And I also cannot access the radio an/or its functions ingame.
I red 1000 pages of forums/sites etc. to find a solution but none worked.
Hope You will have some idea.
Sry, it seems I will give up.
Thank You, as always.