Fixing Apple ID Problems
The single most important bit of data when it comes to iCloud is your Apple ID. One of the problems is that Apple has made it fairly easy to create multiple Apple IDs, but has made it (as of this writing) impossible to merge purchases and other transactions made with different Apple IDs. So your first troubleshooting step is to figure out if the problem you’re facing uses different Apple IDs, and to confirm that the same Apple ID is being used on all devices. For example, I have an Apple ID, and so does my wife. However, we can’t easily share iTunes Store purchases made between each of our Apple IDs. So we standardized on making all purchases through my Apple ID, to which I have given her access. That way, either of us can buy music or books, and the other person can share the items.
If needed, you can manage and reset your Apple ID through http://appleid.apple.com. You can also reset your passwords, addresses, and other personal information here.
One of the iCloud services, Find My iPhone (or iPad or other iCloud-using device) only works with a single iCloud account, so it’s really best to standardize on a single account for all your iCloud related transactions.