AspNet.Identity Creating user with Role

It's the first time I'm working with Entity and Identity and I'm confused about how my user persists. Basically I have a User table, with several relationships with the database and the Id int) I have the Identity AspNetUsers table and AspNetRoles.

I'm trying to create a transaction to ensure that I will not create AspNetUsers without the User and still not add the selected Role in View to a DropDown that I called Profile.

I tried on my UserController the following, in the action create:

[HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult CriarUsuario(Usuario model)
    {
        if (ModelState.IsValid)
        {
            ApplicationUser identityUser = new ApplicationUser
            {
                UserName = model.LOGIN,
                LOGIN = model.LOGIN,
            };

            using (GPSdEntitiesIdentity IdentityContext = new GPSdEntitiesIdentity())
            {
                using (var transaction = IdentityContext.Database.BeginTransaction())
                {
                    var userStore = new UserStore<ApplicationUser>(IdentityContext);
                    var userManager = new UserManager<ApplicationUser>(userStore);

                    IdentityResult resultado = userManager.Create(identityUser, model.SENHA);
                    if (resultado.Succeeded)
                    {
                        resultado = userManager.AddToRole(identityUser.Id, model.Perfil);
                        if (resultado.Succeeded)
                        {
                            if (GravarNaTabelausuario(identityUser.Id, model))
                            {
                                transaction.Commit();
                                return RedirectToAction("Index", "Home");
                            }
                        }
                    }
                    transaction.Rollback();
                    ModelState.AddModelError("ErroIdentity", resultado.Errors.FirstOrDefault());
                }
            }                
        }
        ViewBag.ReadOnly = false;
        return View(model);
    }

The code that persists in my User table is:

public bool GravarNaTabelausuario(string IdUsuario, Usuario model)
    {
        UsuarioEnt UsuarioEnt = new UsuarioEnt()
        {
            IdAspNetUsers = IdUsuario,
            IdPessoa = model.UsuarioEnt.IdPessoa,
            IdStatusRegistro = model.UsuarioEnt.IdStatusRegistro,
            IdUnidade = model.UsuarioEnt.IdUnidade,
        };
        UsuarioNeg UsuarioApp = new UsuarioApp(null);
        if (UsuarioNeg.RecebeRegistro(UsuarioEnt))
        {
            if(UsuarioNeg.ValidaRegistro())
            {
                if (UsuarioNeg.GravaRegistro(UsuarioEnt))
                {
                    return true;
                }
            }
        }            
        return false;
    }

But it only works if I comment on the rows for creating the rollback transaction etc. With the transaction as it is I am having a connection timeout error hit. It appears that the transaction is blocking the table, preventing other inserts and validation queries from running. Can anyone identify where I'm going wrong?