can't restore previous versions from shadow copies

Hi,

I have one files server(2K8R2) for user home shares, and shadow copies is enabled. Recently, I found out that I'm not able to restore some user folders to previous versions, but some without no problems. It gave me the following error.

Windows cannot access \\localhost\E$\@GMT-2014.04.04-20.01.59\UsersHome\xxx.xxx                                             You don't have permission to access \\localhost\E$\@GMT-2014.04.04-20.01.59\UsersHome\xxx.xxx. Contact your network administrator to request access.

It didn't happen to all user share folders, only some of them. Also, I'm able to do the shadow copies restore without the above error if I use UNC path to map to that file server.

I knew there maybe some permissions issue, but how come it didn't happen to all user share folders. Please help........