Access Denied with User in Share ACL, but OK with group

[Guest]

User is getting access denied when accessing his Homeshare; the problem
appears to be with the Share ACL

* Share Perm's currently set explicitly to user's account
* If the ACL is changed to Authenticated Users, access is granted
* Problem occurs on user's main Laptop
* Problem does NOT occur on a test VM, I had him log into
* Both the VM and the Laptop are in the same OU, both are running Vista
Business

I thought I had a wrong user selected.... until the problem did not manifest
itself on the VM.

 

[Guest]

* If I change to a short UNC (\\servername\share$), it works OK.
* But it fails using a FQDN (\\servername.company.local\share$)