User settings for the selection and layout of their dashboard is saved in browser cookies.
Cookies and browser histories are routinely deleted as a troubleshooting tool and when this happens, user settings in PE are wiped out. Many people go to a lot of effort to set up their screens just right and this can quickly be destroyed by deleting cookies.
Seems a better design would be to save these settings in the database. That way your personalized settings are portable and persistent.