We are having this problem with a few teacher laptops. Problem was only occurring when accessing MS Word docs from offline cache, and was happening to random users / laptops.
This is what I did to fix the issue.
1. Disconnect laptop from domain
2. Reboot
3. Logon Locally
4. My Computer > Tools > Folder Options > Offline Files Tab
4a.Click "Delete Files" (repeat until computer says no offline files to delete)
5. Reboot
6. My Computer > Tools > Folder Options > Offline Files Tab
6a.Ctrl + Shift + Click Delete Files (re-initialise offline files)
7. OK and Yes to reboot
8. My Computer > Tools > Folder Options > Offline Files Tab
8a. Untick "Enable Offline Files"
9. Reboot
10. Domain laptop
11. Reboot
12 .Check server permissions for users H:
13. Logon as user
14. Right click H: and sync (repeat a few times)
15. Clear any error messages
16. Test
Hope this helps. (H: is our users home drive)