Grid works fine
<zk>
<zscript><![CDATA[
import java.util.*;
import org.zkoss.zul.*;
List lst = new ArrayList();
for (int i = 0; i < 500; i++) {
lst.add("item " +i);
}
ListModelList model = new ListModelList(lst);
]]></zscript>
<hlayout>
<listbox width="100px" height="300px" model="${model}"/>
<grid width="100px" height="300px" model="${model}"/>
</hlayout>
</zk>
Bug fixed since 2011/07/12