Shadow Copies are working but not showing in previous versions for 1 particular drive.

Hi,

I'm having an issue on Windows 2008R2 where a single drive is making shadow copies yet I am not seeing anything in previous versions.  I can revert the full drive but not restore/browse the previous versions for some reason.

vssadmin list shadows displays all the shadow copies dating back around 1 month, here's an example

Contents of shadow copy set ID: {01b14ae5-3c9d-47e2-8e8c-0aa7c8a3b0db}
   Contained 1 shadow copies at creation time: 02/05/2014 07:02:45
      Shadow Copy ID: {3a5d7210-55c2-4b4f-901f-d95e7f282174}
         Original Volume: (I:)\\?\Volume{1f7f8465-c1f3-11e2-ba7e-005056823ebf}\
         Shadow Copy Volume: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy538
         Originating Machine: svr-fs02.bootham.school.local
         Service Machine: svr-fs02.bootham.school.local
         Provider: 'Microsoft Software Shadow Copy provider 1.0'
         Type: ClientAccessible
         Attributes: Persistent, Client-accessible, No auto release, No writers,
 Differential

Some suggestions are that a reboot will solve the problem but I can't do this in hours.  The event log doesn't show anything of note.

Volume shadow copy service is running and other drive previous versions are showing as expected.

The administrative share is available..............

Not sure what else to check, any ideas?