If your Mandriva 2006.0 installation has a tendency to put the X display server into 100% CPU usage (visible symptoms being sluggish machine and the wee-small-hours scripts not running to completion because they’re too nice(1)), the basic issue is X not coping well with acpid abandoning its socket during a restart (which happens when the acpid log is rotated).
This would normally only happen weekly (early on a Sunday morning), so a workstation user might not notice it and a server might not have X running by default.
You can work around this fairly simply by removing the acpid file from /etc/logrotate.d/ to stop the (typically very small) ACPI log from being rotated. Mandriva promise a permanent fix soon, but they recently published an update with a more elegant workaround which does a logrotate fandango to avoid acpid closing the socket; the traditional “urpmi.update updates; urpmi --auto-select --force” will bring happiness to any afflicted system (presuming, of course, that your update repository’s definition is named “updates“.
I note that Mandriva have also improved their no-version-changes update selection policy to take congnisance of the few “obvious” exceptions like ClamAV.