I can play ogg vorbis or mp3 files with the MediaPlayer. But the sound is quite choppy and cracks quite much. I noticed if I disable a CPU (it's an amd64 dual core), it seems to sound a bit better. Yet if I do something on the system (right clicking on the ProcessController, clicking on a tab in Firefox/BeZilla), then the sound is even more degradated, as if my computer was not powerful enough to handle this. Is it normal in the current state of Haiku?