Clintfan,
I think I read every thread on the internet related to these boards and sound problems, I actually think the thread you mention is the one that put me on the right path towards the solution.
Decided to have a look at my MB (not really believing I would find anything) and indeed found no jumpers were installed. Which I still find very strange for an out of the box board, that doesn't come standard with a front-side panel to install...Can't imagine noone else encountered this....
Anyway the threads on the forums over here helped me solve the problem, so thanks!