I have a SP 2010 Cluster all set up. Its running AD (Active Directory) for authentication and I can login just fine. I need to create a new user account, so I had the window's AD guys create the account, we verified that this new account can log into the domain. I then hopped into SP2010 and it pulled up the user as expected and I granted the user permissions view the site (I just used a generic view permissions group). However when the user tries to log into SP2010 with the account, they can't get in. I tried changing the permission group around, but nothing seems to work.
The user is just stuck at the opening login with the standard windows popup. We have made sure the user is in the correct domain. So I'm thinking the issue is that I missed something in SharePoint, since I'm admittedly new to SP2010 Administration.
Any ideas???