Comment 30 for bug 254326

I'm running Ubuntu Iterpid with standard kernel update on ThinkPad T500.
uname -a
Linux pmslap 2.6.28-15-generic #49-Ubuntu SMP Tue Aug 18 18:40:08 UTC 2009 i686 GNU/Linux

Sometimes (about 1 time each 2-3 weeks) machine under Ubuntu freezes with this notification (it does not happen under WinXp SP3):
Sep 9 16:16:59 pmslap kernel: [17657.688007] BUG: soft lockup - CPU#0 stuck for 61s! [Xorg:3219]
...
Sep 9 16:16:59 pmslap kernel: [17658.760504] BUG: soft lockup - CPU#1 stuck for 61s! [python:3409]
...
Sep 9 16:16:59 pmslap kernel: [17723.184005] BUG: soft lockup - CPU#0 stuck for 61s! [Xorg:3219]
...
Sep 9 16:16:59 pmslap kernel: [17724.256504] BUG: soft lockup - CPU#1 stuck for 61s! [python:3409]
...
the last sentence in syslog is:
Sep 9 16:16:59 pmslap kernel: [17773.265065] thinkpad_acpi: fan watchdog: enabling fan

Im using thinkpad_acpi fan controler because of other Ubuntu serious bug - the fan by default is never reaching maximum rotation possible, the bug is reported here:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/213818