Editing the registry as described in the second post did the trick. I changed the default value from 32 to 2 and to 1, and in both cases performance is much better (Core i3). Thanks, Jesse!

3. I've found Xara 5 interacts poorly with certain 3rd party software, such as clipboard managers. It might be something else on your system messing with it.
I did a clean install just two days ago. The system is fresh, and it's pretty bare bones. I don't even have real-time virus protection installed.