Bug 144556 [Dialogs] TitleAreaDialog fails to properly recreate when an instance is reopened
When a TitleAreaDialog is created, opened, closed and opened again on the same instance the messageArea is not properly checked against disposal when it is accessed in setWarningMessage throwing an SWTException for disposed when the message area is updated the second time the dialog is opened.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/TitleAreaDialog.java
*            int The spacing between widgets on the horizontal axis.
     */
    private void setLayoutsForNormalMessage(int verticalSpacing,
            int horizontalSpacing) {
        FormData messageLabelData = new FormData();
        messageLabelData.top = new FormAttachment(titleLabel, verticalSpacing);
        messageLabelData.right = new FormAttachment(titleImageLabel);
        messageLabelData.left = new FormAttachment(messageImageLabel,horizontalSpacing);
        messageLabelData.height = messageLabelHeight;
        if (titleImageLargest) {
			messageLabelData.bottom = new FormAttachment(titleImageLabel, 0,
                    SWT.BOTTOM);
		}
        messageLabel.setLayoutData(messageLabelData);
        FormData imageLabelData = new FormData();
        imageLabelData.top = new FormAttachment(titleLabel, verticalSpacing);
        imageLabelData.left = new FormAttachment(leftFillerLabel);
        imageLabelData.right = new FormAttachment(messageLabel);
        messageImageLabel.setLayoutData(imageLabelData);
        
        FormData data = new FormData();
        data.top = new FormAttachment(titleLabel, 0, SWT.TOP);
        data.left = new FormAttachment(0,H_GAP_IMAGE);
        data.bottom = new FormAttachment(messageLabel, 0, SWT.BOTTOM);
        leftFillerLabel.setLayoutData(data);       
               	
     }
    /**
     * The <code>TitleAreaDialog</code> implementation of this
     * <code>Window</code> methods returns an initial size which is at least