Hflex fail when place the listbox in the second tab of the tabbox (IE8 only)

 
<zk>
	<tabbox>
		<tabs>
			<tab label="tab" />
			<tab label="tab" selected="true" />
		</tabs>
		<tabpanels>
			<tabpanel></tabpanel>
			<tabpanel>
				<listbox height="150px" width="150px">
					<listhead>
						<listheader label="aaa" hflex="min" />
						<listheader label="bbb" hflex="min" />
						<listheader label="ccc" hflex="min" />
					</listhead>
					<listitem forEach="1,2,3">
						<listcell label="aaaaaaaa" />
						<listcell label="aaaa aaaa" />
						<listcell label="aaaa aaaa" />
					</listitem>
				</listbox>
			</tabpanel>
		</tabpanels>
	</tabbox>
</zk>