Orbeon is ignoring oxf.epilogue.theme?

Question

I'm using Orbeon 4.4.0.201311042036 PE

I am trying to set a theme for the form builder by using these two properties in properties-local.xml

<property as="xs:anyURI" name="oxf.epilogue.theme" value="oxf:/config/theme-plain.xsl"/>
<property as="xs:boolean" name="oxf.epilogue.use-theme" value="true"/>

I have modified the /config/theme-plain.xsl to add a custom header to the page.
I have also tried creating a new file (for example: /confg/theme-custom.xsl) and pointing the property to that, but Orbeon is completly ignoring the property.

By using the url parameter: ?orbeon-theme=plain I am able to activate the modified theme-plain.xsl, but ?orbeon-theme=custom does not activate the theme-custom.xsl. (also pressing any button, ie. "Home" removes the url parameter and the theme)

How do I configure Orbeon use a theme?

Answer 1

Alessandro has answered the question and I have verified that the solutions works great. Thanks.

See: http://discuss.orbeon.com/Orbeon-is-ignoring-oxf-epilogue-theme-td4657765.html