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
IPreferencePage {
    /**
     * Preference store, or <code>null</code>.
     */
    private IPreferenceStore preferenceStore;
    /**
     * Valid state for this page; <code>true</code> by default.
     *
     * @see #isValid
     */
    private boolean isValid = true;
    /**
     * Body of page.
     */
    private Control body;