Basically the the preferences consists of a set of checkboxes in a menu, and a dialog of various options. Changing values and clicking "Ok" in the preferences dialog should have an immediate effect on the program. Since there are many options, this checklist will not elaborate on the test cases. Instead, the tester should practice changing options and observing their affect on the program.
Regarding the rule of preference changes taking effect immediately, please note the following exceptions:
Below are some items to try to verify that the preferences are working at the most basic level.