Example Code:

package application;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ProgressBar;
import javafx.scene.layout.VBox;


public class Main extends Application {

private double progress = 0;

@Override
public void start(Stage primaryStage) {
try {

VBox root = new VBox(10);

ProgressBar progressBar = new ProgressBar(-1);
progressBar.setPrefSize(200, 20);

Button increaseButton = new Button("IncreaseProgress");
increaseButton.setOnAction(new EventHandler<ActionEvent>() {

@Override
public void handle(ActionEvent event) {
progress += 0.1;
progressBar.setProgress(progress);
}
});

Button resetButton = new Button("Reset");
resetButton.setOnAction(new EventHandler<ActionEvent>() {

@Override
public void handle(ActionEvent event) {
progress = 0;
progressBar.setProgress(-1);
}
});

root.getChildren().addAll(progressBar, increaseButton, resetButton);

Scene scene = new Scene(root,400,400);
scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
primaryStage.setScene(scene);
primaryStage.show();

} catch(Exception e) {
e.printStackTrace();
}
}

public static void main(String[] args) {
launch(args);
}
}




 When clicking the "Increase Progress" Button, the ProgressBar switches from indeterminate to determinate mode. The ProgressBar starts from the wrong position (depending on the spinners location).

Worked fine with 8u5, doesn't work with 8u20.