Erro conexão com Firebird

import java.sql.*; 

public class Conexao { 

	public Connection con=null; 
   	public Statement stm; 
  
   	public Connection getConect() { 

    	try { 
    	    Class.forName("org.firebirdsql.jdbc.FBDriver"); 
			con = DriverManager.getConnection( "jdbc:firebirdsql:192.168.1.2/3050:C:/Temp/banco.gdb", "SYSDBA", "masterkey");
       	} 
       	catch (Exception e) { 
        	System.out.println("Não foi possível conectar ao banco: " + e.getMessage()); 
      	} 
		return con; 
   	}
 

	public Connection desconnect() {
	 
    	try { 
    		con.close(); 
    	} 
    
    	catch(Exception e) { 
    		e.printStackTrace(); 
    	} 
    	return con; 
	}
	
	public static void main(String args[]) {
    	
            Conexao c = new Conexao();
            c.getConect();        
    }	
}

CLASSPATH = %JAVA_HOME%\lib;.;%JAVA_HOME%\lib\tools.jar; 
JAVA_HOME = C:\j2sdk1.4.2_04