Sound is sparky/choppy

[Fredagsmys]

I just installed the penumbra collection on Ubuntu 9.04 and the sound is really strange.

Some time ago I've managed to get the demo working fine on ubuntu 7.10.

I have a built in sound card, I think it is an ac -97 something.

The strange thing is that sometimes when I start the game, the sound is fine, but that has only happened to me once yet. .

Has this something to do with ubuntu or is there a patch somewhere in the making that will solve this?