I hope this doesn't sound like BS but...
I installed the Dude just after release of the first beta on Windows XP prof. I later found that when I clicked a link to a web page in an Outlook email message that the page would take a very long time to open (several minutes). Thinking it was usual MS behaviour after the machine had been in general use for about 3 years, I re-installed XP on a new hard drive in the same machine.
All was fine until I re-installed latest release of the Dude and now I have the same problem. The problem goes away when Dude server is stopped.