Currently Being ModeratedOct 31, 2011 11:38 AM (in response to Hemslow)
Under Settings > Mail, Contacts, Calendars > Fetch New Data > ... do you have Push set to On? And under that, at the bottom of the Fetch New Data screen, when you click Advanced, is your iCloud account set to Push rather than Fetch or Manual?
Currently Being ModeratedOct 31, 2011 1:00 PM (in response to mollib)
Yes - I have both those settings set to Push.
I really don't know what's changed, I was running iOS5 for a week or so using MobileMe before I switched to iCloud (as I was waiting to upgrade to Lion) and everything was working fine. It's only since I migrated my account to iCloud that it's not pushing properly.