I can't find much on the issue myself however does anyone know why a user NK2 file would lose its contents seemingly overnight? After a user reports their cache missing, I see that the NK2 file is still there named correctly, however with 0kb size. It's as if the file just resets itself. New entries can then be added as if it was a new profile, however all previous contents is lost.
This is easily fixed with a restoration from backup, however it's frustrating for users who it continues to happen to. The size of the NK2 files range anywhere from 200-500kb, so it's not like they 'over fill' due to size..
Any ideas on the cause/permanent solution? Outlook 2007 and Exchange 2010.