Music and Sound Crash?

[BlackSniper]

Everytime when I join Official Event, I first can't hear the music after few minutes. And then few minutes later I also can't hear the sound effects like shooting arrows, hitting enermy's, pickup weapons, spawning players etc.
I have realy no idea what it is, It comes from Nord Invasion itself.
Does someone have any idea's how to fix this? Also would be happy to know when NI can run on newest patch from Warband..
Mayby it's already and I didn't hear that, so my music and sound crash? Help please!