Ever since I started syncing my Contacts and Calendars on my Mac with iCloud, I've noticed that stuff sporadically disappears.
I've had to re-add an event to my Calendar 3 times now, and many of my Contacts mysteriously vanish after a couple of days.
The only other device that syncs with iCloud is my iPhone, but I still lose events and contacts even if I don't make any changes on my iPhone.
What is going on, and how do I prevent this data loss?
Per Emil's suggestion, I contacted Apple's support team for assistance. They recommended that I enter all my contacts into iCloud directly (via icloud.com), then delete my iCloud account from all my devices and finally set up iCloud for each device again.
It's been a few days, and so far, the problem seems to have gone away (:
I have experienced the same for a while now – but only at the slightly unstable network at school. I think the network-connection might be the issue in some cases.
Alteratively, it might be that the syncing process doesn't detect your changes, and therefore owerwrites the original content with the content already stored in the cloud.
Bottom line, I'm not quite sure, I suggest you start a chat with Apple directly and ask them about it.
