The new IOS6.2 update doesn't synchronise with Ipad 2 with Ipad mini it does it well

Did you check Settings>iCloud>Calendar and make sure that it is still turned on on the iPad?

Did you refresh the calendar in the calendar app on the iPad by Tapping the calendars button in the upper left corner of the calendar app and then tap the circular arrow icon?

Do you have the correct calendar selected in the calendar app?

If you set an event on the iPad2 does it show up on the phone and the iPad mini - but it does not work the other way around? If you set an event on the phone or the iPad mini - it doesn't show up on the iPad2?

I'm no expert with using iCloud, but have you tried quitting the calendar app on the iPad2, reboot the device and then see if the calendars will sync?

In order to quit the calendar app, Go to the home screen first by tapping the home button. Double tap the home button and the recents tray will appear with all of your recent apps displayed at the bottom. Tap and hold down on any app icon until it begins to wiggle. Tap the minus ➖ sign in the upper left corner of the calendar app. Tap the home button or anywhere above the task bar.

Reboot the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider if it appears on the screen - let go of the buttons. Let the iPad start up.

What a minute or so after the iPad restarts and then go to the calendar again, and refresh the calendar and see what happens.

if that doesn't help, try Apple's troubleshooting steps here.

Great. Glad that you got it working again!