We are having a problem with one of our unc shares on server 2008 enterprise. The share has been working for a while and just yesterday it started having problems. When you type \\servername\share in a run command you get a access denied even though the users have full control on the ntfs permissions and everyone has full control on the sharing permissions. Other times the share will open up and the folders have gray X's on them like they are offline. If you type \\ipaddress\share it opens up no problem. This led me to believe it was a dns issue but the dns records look correct.
Troubleshooting Done:
re-did the share
disabled the AV
check dns settings.
reboot switches
reboot the server and DC's
