Entity Framework not updating data in database with update

I am trying to insert/update data into a table using Entity Framework 4.1 from an Edit action in my MVC3 controller with the following code:

[HttpPost]
public ActionResult Edit(UserDetailsForm form)
{
    try
    {
        if (ModelState.IsValid)
        {

            UserProfile up = cpctx.UserProfiles.Where(w => w.UserNam开发者_运维知识库e.Equals(form.email)).SingleOrDefault();
            if (up == null)
            {
                up = new UserProfile();
                up.UserName = form.email;
                up.FirstName = form.FirstName;
                up.LastName = form.LastName; 
                ctx.UserProfiles.Add(up);
            }
            else
            {
                up.FirstName = form.FirstName;
                up.LastName = form.LastName; 
                cpctx.Entry(up).State = EntityState.Modified;
            }



            ctx.SaveChanges();

            return RedirectToAction("Index");
        }

        return View(form);
    }
    catch
    {
        return View(form);
    }
}

Everything works fine for an new record and I get a new row in the database, my problem occurs when updating. The code executes without any exceptions and I can see the values in up correctly in the watch window, however, when ctx.SavesChanges() is executed the database is not updated.

Any help in resolving this issue will be greatly appreciated.