NUnit Gets Different Hash Code Values from ReSharper vs Visual Studio 2013

I have a fairly simple GetHashCode() implementation in C# as per Jon Skeet's answer here. Here is my code:

public override int GetHashCode()
{
    unchecked
    {
        int hash = 17;
        if (Title != null)
        {
            hash = hash * 23 + Title.GetHashCode(); // Title is of type string
        }
        return hash;
    }
}

When I run an NUnit test targeting this method through Visual Studio 2013's Test Explorer I get one value for the hash code and when I run it through ReSharper 8's Unit Test Explorer I get a different value.

Here is my unit test code:

[Test]
public void GetGetHashCode_WithLinkAndTitle()
{
    const int expected = -1272954771;
    var target = new Article
    {
        Title = "Rumble News"
    };
    var actual = target.GetHashCode();
    Assert.AreEqual(expected, actual);
}

From VS 2013 I get actual == -1411317427 and from ReSharper I get actual == -1272954771.

Why are the values returned from GetHasCode() different across test runners and how can I make them consistent with each other?