The Length function does not take any arguments. But when you pass it one - for example
var albums = Database.Open().Albums.Select(db.Albums.Title.Length(123));
you get the following exception.
Query returned a Simple.Data.SimpleQuery
The len function requires 1 argument(s).
The message is wrong for two reasons : its the Length function and it requires 0 arguments.
It should also be throwing an ArgumentException.
Unfortunately that's just wrapping a SqlException and I'm limited as to what I can do.