updated 06:55 pm EDT, Thu October 20, 2011
Bug puts mobile iWork users at high risk of loss
Reports are coming into Apple's support forums that a serious bug in the way iCloud syncing is handling iWork documents -- those created by Pages, Numbers or Keynote -- is causing the files to be deleted upon a fresh sync, leaving mobile iWork app users in particular with lost documents and no apparent way to get the work back (Mac users can recover the documents via their Time Machine or other backup devices).
The effect has not been seen on other types of iCloud syncing, just iWork documents that are synced to iCloud from or to mobile devices. Although the issue is still being tracked down by users comparing notes on Apple's support forums, the problem appears to be that iWork documents are being moved automatically into a auto-delete folder when they shouldn't be. Some desktop users have reported recovering their work from the folder, which is found in the hidden (in Lion) user Library under the name "Mobile Documents" and/or "Mobile Documents.delete.(date)".
For mobile iWork users, the problem is much worse, as iCloud syncing is the main way users expect their work to be backed up. During the iCloud sync, all copies of the file on all computers or devices that have been synced are deleted, according to reports. It's unclear if this problem is affecting all iWork users who have upgraded to iOS 5 and turned on iCloud syncing for iWork documents or just a small group, but it has spawned several threads, each with a dozen or more users.
For now, the main recommendation seems to be turning off iWork document syncing with iCloud to simply avoid the issue entirely. Some users have said that completely resetting iCloud (turning off all services on all devices and then re-establishing iCloud after deleting the "Mobile Documents" folders in their Mac's user library) may resolve the issue, but it's unclear if that fix restores permanent syncing stability. It is also difficult for most Mac users to located the user library file, since it is hidden by default in Lion (third-party free programs such as Lion Tweaks can be used to make the user library visible again).
Users who have already lost work may try looking in the user library of their desktop or notebook device to see if the "Mobile Documents" folder is there and the files are still within it, but if not there is not at present any recovery path. Users are encouraged to report the issue to Applecare even if they are out of warranty, or use the iCloud feedback page to report the issue.
Apple has not yet officially responded to the issue, but users should turn off iCloud syncing of "Documents and Data" on iOS 5 devices until the issue can be tracked down and resolved, and fall back to e-mailing the documents or using third-party cloud storage as a way of transferring them from mobile to desktop or notebook devices as was done before iCloud debuted.