I don't see any malware in your log. I was looking to see where winlogon.exe was running from. The C:\WINDOWS\system32\ folder is the right one. Alot of viruses use the name winlogon.exe but run from the C:\Windows or C:\Winnt folder. So you are pretty much set there.
Another thing that sometimes gets the winlogon process humming at high cpu usage is spoolsv.exe when there is a print job waiting. Try opening taskmanager and shut down spoolsv.exe and see if the cpu useage drops. If it does, check to see if a job is waiting to be printed.
That's about all I can come up with, right now, software wise. If you're still having the problem, checking out Digitalic's suggestion would be the next step.
Let us know how it goes...
PS: I notice that you are running XP without any service packs. I also see no antivirus program or firewall running.
I'm amazed you're not having malware problems.