Bug 73027 [Dialogs] Buttons are too high
I20040831 Buttons are no longer oval but have a rounded rectangle shape (see first screenshot). The second screenshot shows how buttons using the small system font should look like.
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferencePage.java
* </p>
     *
     * @param parent the button bar
     */
    protected void contributeButtons(Composite parent) {
    }
    /**
     * Creates and returns the SWT control for the customized body 
     * of this preference page under the given parent composite.
     * <p>
     * This framework method must be implemented by concrete subclasses. Any
     * subclass returning a <code>Composite</code> object whose <code>Layout</code>
     * has default margins (for example, a <code>GridLayout</code>) are expected to
     * set the margins of this <code>Layout</code> to 0 pixels. 
     * </p>
     *
     * @param parent the parent composite
     * @return the new control
     */
    protected abstract Control createContents(Composite parent);
    /**
     * The <code>PreferencePage</code> implementation of this 
     * <code>IDialogPage</code> method creates a description label
     * and button bar for the page. It calls <code>createContents</code>
     * to create the custom contents of the page.
     * <p>
     * If a subclass that overrides this method creates a <code>Composite</code>
     * that has a layout with default margins (for example, a <code>GridLayout</code>)
     * it is expected to set the margins of this <code>Layout</code> to 0 pixels.
     */