If you are using the people picker column in a list, watch out. You could be faced with an odd little issue.
Recently, I created a list to control the views in an InfoPath form. This list uses a people picker column that pulls the “UserName”. What I noticed was that three of the users were displaying differently. Instead of all lowercase letters, the first two letters of the username were capitalized. As it happens, one of those users was unable to see a certain view that they had access to.
I had our AD guy change the names of the users to all lowercase letters. I then ran a full AD import into SharePoint. I waited a little while, pressed CTRL+F5 on my keyboard and noticed that the name changed in the permission checking list.
I logged in as the user and was now able to see the correct view. Weird huh?