iMore

I use iPnone4, iPad and my laptop pc and sink them up with iCloud. Maddress book and contacts list work perfectally bu my calendar will not sink with my iPad but it does sink with my iPhone and pc. I have checked all of the controls on the iPad and they are set correctly. I udgraded my system to 5.0.1 but still can't get my calendar to sink with my iPad. Can someone tell me what I'm doing wrong?
Thanks.