Cannot work with Windows Journal files in a re-directed folder

This is our first experience with a tablet PC user whose "My Documents" folder is re-directed in Group Policy to a network location.  Everything seems to be sync-ing properly, and he can create, save, and modify most files, but Windows Journal files (*.jnt) are throwing up errors AFTER they are saved.  (Permissions to the folder appear to be correct for all other file operations.)

1)  We can "Save" Journal files once.

2) We can "Save As" Journal files indefinitely, as long as we assign a new file name each time.

3) Even if a saved Journal file has never been closed, any attempt to save changes fails with "an error occurred."

4) When we attempt to open a saved Journal file, the system indicates that the "file may be in use by another program" - even after re-boot, and we're certain that no one else can have the file open.

Any ideas will be greatly appreciated!!!