Runo theme shows broken button images on Windows 7, last Google Chrome

you can see that buttons’ borders look weird.

is this some known problem?

I’m using Vaadin 6.7.8. Note: it works fine with Internet Explorer 9.0

    HorizontalLayout buttonsLayout = new HorizontalLayout();

    Button saveButton = new Button("Save");
    saveButton.addListener(new Button.ClickListener() {
        @Override
        public void buttonClick(Button.ClickEvent event) {
            save();
        }
    });
    buttonsLayout.addComponent(saveButton);

12320.png