Version 11.0.1.2467 have a new BUG in .NET driver.

If you try to execute a sql with string parameter it's throws an exception Not enough values for host variables.

It works fine using int parameters. Didn't try with another types.

Here is a sample application.

class Program
{
    static void Main(string[] args)
    {
        var factory = DbProviderFactories.GetFactory("iAnywhere.Data.SQLAnywhere");

using (var connection = factory.CreateConnection())
        {
            connection.ConnectionString = "my connection string";
            connection.Open();

try
            {
                using (var command = connection.CreateCommand())
                {
                    command.CommandText = "select count(*) from DUMMY where (dummy_col = ?)";
                    command.Parameters.Add(factory.CreateParameter());
                    command.Parameters[0].Value = 1;

Console.WriteLine("[Int] {0} records found.", command.ExecuteScalar());
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Int Exception: {0}", ex.Message);
            }

try
            {
                using (var command = connection.CreateCommand())
                {
                    command.CommandText = "select count(*) from DUMMY where (cast(dummy_col as varchar(10)) = ?)";
                    command.Parameters.Add(factory.CreateParameter());
                    command.Parameters[0].Value = "1";

Console.WriteLine("[String] {0} records found.", command.ExecuteScalar());
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("String Exception: {0}", ex.Message);
            }
        }

Console.ReadLine();
    }
}

WORKAROUND use build 2427