KUbuntu 8.10 Intrepid freezes machine after some time of inactivity

[Azamat S. Kalimoulline]

Kubuntu 8.10 Intrepid 32-bit fresh install
lspci -vvnn and cpuinfo given in attachement.
Machine freezes after some time of inactivity and while trying finish kde session
After upgrading to kde 4.1.3 I do not see freeze while session finish, but freeze after time of inactivity still there.
This reproducable on my machine when left it about 40 minutes (using info from syslog from last freeze).
No messages in logs, no other actions. Only freeze. It is annoying for me.
Now I tried to disable KDE desktop effects. About that results will write here.

[Azamat S. Kalimoulline (turtle-bazon)]

When I use Kubuntu (activity time) all fine.

[Azamat S. Kalimoulline (turtle-bazon)]

Also was Interesting situations:
1. I've upgraded to KDE 4.1.3 and left machine. So, It freezed.
2. I've updated my kdelibs (today) and left machine. It freezed again.

All generic, but after that I've lost my some settings: e-mail accounts in Kontact, Identity and Accounts in Koete, UI settings (my panels and widgets on it).
After another freeze (not after upgrade), settings not changed.

[Azamat S. Kalimoulline (turtle-bazon)]

Disabling desktop effects has no effect. So, problem still here.

[Azamat S. Kalimoulline (turtle-bazon)]

Perhaps, problem in using realtime kernel. I've back generic kernel and my shutdown works properly, also suspend to ram and disk works properly. I'll test it while and will write here about results.
Why I think on rt-kernel? In attachments in syslog can be found BUG: entries. With generic kernel I do not see it.

[Azamat S. Kalimoulline (turtle-bazon)]

Using generic kernel all works almost fine. No freezes, no problems. Only one moment. I left my desktop station locked last night. This morning kde session was terminated and I saw login screen. I do not know why. May be, bug in kde, may be, another.

[Azamat S. Kalimoulline (turtle-bazon)]

Problem was not in kde, in realtime kernel I used.