Need help with newest opera, some expert advice needed

I have been trying for days to get my opera browser to..

1) play sound from websites like ytmnd, only some play.
2) play windows media files in the browser, I have installed the latest media player and the netscape plugin tons of times, and it wont work.

Can anyone point me out as to how I can do these

I'd post on the Opera Forum for help-

Also, make sure in the Opera Prefernces / Advanced / Programs that the default applications are listed.