Hey Bob
Make sure the account trying to access the folders in the User folder have NTFS permission to do so. In other words, not just permission in the Share properties, but in the Security properties tab as well.
Windows will first check the Sharing permissions to see if you can access the share. If you can, it will then check the file properties (Security tab) to see if you can access the file.
A "quick and dirty" practice some network admins use is to give the "Everyone" account Read and Write permissions in the Share. Then restrict actual access at the NTFS level. Hope this helps.