Sometimes a calendar event may not immediately appear on your iPod screen when you select Extras > Calendars. This delay occurs when iPod is still loading calendars. This can happen with any iPod model (including iPod, iPod photo, and iPod mini) that has the Calendar feature, and can occur after you've synced iCal calendars to your iPod with iSync, or manually copied this information to your iPod.
You may experience a short delay after you first copy or sync a large number of contacts and calendar events, or after you reset iPod. When iPod first loads a large number of contacts, it displays a progress indicator before displaying the contacts. However, iPod does not display a progress indicator when it loads a large number of calendar items. Instead, just wait about 10 seconds and then try to view your calendars again.