Good,
dropped the old answer. After several searches, I found a way to do this.
ImageIcon icon = ..[the animated gif without looping]..
....
label1.setIcon(icon);
....
label1.setIcon(null);
icon.getImage().flush();
label2.setIcon(icon);
....
Java Api: Image # flush ()
. label1.setIcon(null);, 2. label1 .