Good day!

The last couple of months, I've been annoyed with the following problem:

In the morning, when I boot up my PC, it will freeze just after login, or when I've been busy for about a minute. Alternatively, it restarts just like that, without any warning. Sometimes it happens just once or twice and then I can continue all day without any problems, but sometimes, I have to restart at least 5 times before my system seems to "stabilize". Surely this can not be normal.

I'm not sure, but I think it's somehow related to this system log message (although I don't know what it means):

2009-06-14 09:33:17 blackbird pulseaudio[12558] alsa-util.c: Cannot find fallback mixer control "PCM" or mixer control is no combination of switch/volume.
2009-06-14 09:33:18 blackbird pulseaudio[12558] alsa-util.c: Cannot find fallback mixer control "Mic" or mixer control is no combination of switch/volume.

Anyway, I think it has something to do with PulseAudio (which I cannot remove without removing Ubuntu-desktop). So now I'm using KDE, hoping the problem will not show up anymoren.
But I like Gnome more, so I would really like to fix this.

Any ideas?

Thanks a lot!

Maarten

PS: I use ubuntu 9.04, fresh installation, but this problem also occured with previous editions...