Portlet styling

I'm not sure this is an ICEfaces problem per se but I'm having some difficulty creating dynamic styles for a portlet hosted in Liferay.

If I do:

<ice:portlet styleClass="whatever">

the style "whatever" is correctly written to the "div" tag in the HTML. However, if I do:

<ice:portlet styleClass="#{mainStyleClass}">

and pass mainStyleClass in as a parameter (the portlet declaration is in a template), it doesn't work. To test that the parameter is working, I write:

<ice:outputLabel value="#{mainStyleClass}" />

and the output works, so the parameter is being passed correctly.

Any ideas?