Hi hep, the problem is with the iframe style that's added near the end of moi-black.css :

iframe {
    padding:5px 10px;
    max-height:5em;
    border:1px solid #686868 !important;
}

The Options dialog uses iframes for that area you show, and that max-height property is getting applied to them. So you can fix it by removing the iframe rule or by removing just the max-height in it.

- Michael