iPod Touch calendar not synching with Outlook 2010, iPhone 4 synching okay

Why has my iPod Touch recently stopped synching calendars with Outlook 2010 on a Win 7 PC, while my iPhone 4 is still synching calendar, contacts, etc. just fine with Outlook 2010 on a Win 7 PC?

Before the recent iTunes upgrade, both iPod and iPhone synchronized calendars with Outlook just fine. Now the iPod isn't working. Recurring meetings are still on the iPod, but not new meetings.