I tried the /cleanviews switch already. When I switch between messages
as the preview pane is enabled, the CPU goes to 100%. The Outlook
process consumes all of it. I have looked at the indexer (Windows
Desktop Search installed) and McAfee, but can rule them out with
reasonable certainty. This is a Laptop 1.6 Ghz, 1 GB RAM, 20+ GB free
disk. No Exchange involved, just plain POP3 email. It happens when I am
online or offline. Ran Spybot, machine seems free of Spyware. Any ideas
what to look for? Thanks.

Issue was now experienced when simply navigating from one message to
another, when changing calendar views, or browsing the address book. In
short: everywere.

May have found the solution... read somewhere else that the file
outcmd.dat may be a culprit when performance is issue. It is located in
\documents and settings\[username]\application data\microsoft\outlook.
I closed Outlook, created backup of all file in this dir, then deleted
the content of the dir. I let the directory stand, thought.

Restarted Outlook, it seems to re-create whatever it needs in this dir
(outcmd.dat was re-created, as well as an srs and xml file).

Have not seen performance issues since. However, I am also starting now
with a fresh PST file - just to be safe.

Oooops..... I forgot. I also checked in the Control Panel -- Mail
Under *Data Files*. I found two references in there to the same PST
file. There should have been only one. I also removed this duplicate
entry. I am guessing that the combination of deleting the outcmd.dat
file and the removal of the duplicate data file entry may have solved
this. Of course, I will monitor this for a while.