hflex fails when combining hbox and templating

main_reprod_unrolled.zul

• shows that the layout is working and the window resizes proper to use up the available space as indicated by hflex="1" on the surrounding hbox and window -> OK

main_reprod.zul
composing the same layout with a template the hbox fails to propagate the calculated hflex width to the window and it remains at the minimum size required to display the div inside of it

the difference between the generated markup can be seen in this screencast: http://screencast.com/t/1lPW7oawZ

(workaround: if possible - replacing the <hbox> with an <hlayout> does not have this issue, that the results are different between the template and non template version)