The user can view the site, they simply always receive "ERROR: Access Denied". The error message also picks up their domain\user as expected.
I am using SharePoint 2010.
The SharePoint server is in another domain than the user however there is a trust relationship between the two. My user, is also in the same domain as the other and I can access the site as expected...what the hell!
I have checked, the user is a member of two SharePoint groups within the site however they have no other permissions. I have tried it on a few users and they all have the same problem.
I believe the problem is something to do with SharePoint not being able to accept users from the domain, I just don't know where to start looking anymore?
edit -I now see a sharepoint stack exchange..sorry
Ultimately my problem was probably site specific. The users I were trying to add were from a second domain. This domain does have a trust to my primary domain and as such I should have been able to add groups directly to my sharepoint instance. Unfortunately I couldn't.
My work around was simply to create a SharePoint group and add the users (from the second domain I must add) directly. This works fine.
I actually don't know the reason why the AD groups didn't work but the individual users did...if anyone has any insight let me know.
Thanks