Recently I was trying to fetch a SPField from a SPWeb object. I had SharePoint 2010, so I decided to use the new SPFieldCollection.TryGetFieldByStaticName() Method.
You can imagine how surprised I was, that I couldn’t get the field I was looking for. What do we learn? Well, the StaticName of an SPField is not necessarily the InternalName!
Here is a link to the MSDN about SPField.StaticName: http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.spfield.staticname.aspx