1 which Timer are you using java.util.Timer or javax.swing.Timer?
java.util.Timer Constructors are Timer() or Timer(boolean isDaemon) and you must schedule them. See the API.
http://java.sun.com/j2se/1.4.1/docs/api/java/util/Timer.html
javax.swing.Timer Constructor is Timer(int delay, ActionListener listener) BUT the ActionListener is really an Action. See the API.
http://java.sun.com/j2se/1.3/docs/api/javax/swing/Timer.html
and look here for an example.
http://java.sun.com/products/jfc/tsc/articles/timer/
what benc was trying to point out is that you may need to fully qualify the Timer. If you imported the util package, the Timer in your program may be trying to use that instead. So use javax.swing.Timer t = new javax.swing.Timer(500, new TimerAction());