Sometimes, for whatever reason, the permissions that determine who gets to see what in a given share or folder can get messed up. This isn't a specific DrivePool thing so much as a Windows thing, and usually not so much a bug as just an undesirable side-effect of how NTFS permissions work when you've moved drives between machines, operating systems, users and/or pooling applications. Anyway, here's a fix.
To set friendly (not necessarily original, but WHS/DP friendly) permissions on a folder:
* use Explorer to view the folder on the DP drive
* bring up its context menu (usually right-click), go to Properties, Security tab, Advanced, Owner, Edit
* choose Administrators, tick Replace, then OK, OK, OK, OK
* again bring up its context menu, go to Properties, Security tab, Advanced, this time Change Permissions
* remove all non-inherited permissions, tick Include and tick Replace, then OK, Yes, OK, OK
* check that the inherited permissions now include SYSTEM and Administrators, both Full Control.
* if not, add them.
If the above folder is also shared (this does not include a sub-folder of another shared folder):
* use Dashboard to view the folder's properties
* change the Sharing permissions to None for all, apply, then change them to what you want and apply.
That should do it. If it doesn't, your permissions might be even more whacked than usual; consult your local NTFS guru.