Firebird backup on C#?

Question

I am backing up a Firebird database on C# but is returning the following error:

unrecognized service Parameter block

Follow my code below

string cmBackup = @"C:\Controle Escolar\Ano_2011\Banco de Dados\Backup\BACKUP_" + agora.ToString("dd_MM_yyyy") + ".GBK";

string cmBanco = @"C:\ProjetoLeMarc\LermarcSistemas\LermarcSistemas\bin\Debug\SISTEMABD.FDB";
string conexao = @"ServerType=1;User=SYSDBA;Password=masterkey;Port=3050;Dialect=3;DataSorce=localhost;Database=C://Banco;"

FbBackup backupSvc = new FbBackup();
backupSvc.ConnectionString = conexao;
backupSvc.BackupFiles.Add(new FbBackupFile(cmBackup, 4096));
backupSvc.Verbose = true;
backupSvc.Options = FbBackupFlags.IgnoreLimbo;
backupSvc.Options = FbBackupFlags.NonTransportable;
backupSvc.ServiceOutput += (sender1, e1) => Console.WriteLine(e1.Message);
backupSvc.Execute();