Normal Try using "shift" and "arrow" keys to select multiple values. In IE browsers, after two items were selected, the "two-item" selection shifted to the next two when pressing "down" arrow key. The selection should expand to include more items.
test.zul
<listbox multiple="true" mold="select"> <listitem label="test1" /> <listitem label="test2" /> <listitem label="test3" /> <listitem label="test4" /> <listitem label="test5" /> <listitem label="test6" /> <listitem label="test7" /> <listitem label="test8" /> <listitem label="test9" /> </listbox>