Can't fix an user account in Mavericks (frozen)
First step I would recommend is to restore the users account permissions also called ACL's. The ACL's get messed up sometimes leading to kind of problems you are having.

To do that use the following steps:


Hold Command-R during restart.
Select Terminal and run resetpassword.
Select the account in question.
Do not reset the password. 

Instead click on the Reset Home Folder Permissions and ACLs at the bottom right.