ALSA engine doesn't work

Hi, I have problems with the ALSA sound engine in SL. This problem is identical in CoolSL.
Esound produces choppy audio, so unacceptable.
OSS works perfectly, but ties up the soundcard, so it is a niusance.

So I thought ALSA would be the right choice. It works for a few minutes.
Eventually, the CPU goes crazy busy, and then i will lose keyboard input, i.e. can't even type in other apps, Ctrl-Alt-F1 Ctrl-Alt-Bksp are all dead, Alt-Sysrq sequences also dead.
As soon as i kill -9 the SL client, my system returns to normal.

Also if I do new things in SL like explore, the bug triggers much more quickly, say 2-5 minutes.
If I do routine things like chat to people, it may take 1 hour to trigger.

Is it just SecondLife, or does anything which uses ALSA behave the same way? What if you just play a WAV file with the command line aplayer?