Primefaces selectOneMenu displaying when label is empty

For some reason selectOneMenu is showing   when selecting an option with an empty label.

When first loading the page, it works fine, but if I select the blank option in my list, it displays  

<p:selectOneMenu id="eyeColor" editable="true" value="#{model.eyeColor}">
    <f:selectItem itemLabel=" " value="#{null}"/>
    <f:selectItems value="#{selectionList.getSelectList(SelectListDefinition.SELECT_EYE_COLOR)}" />
</p:selectOneMenu>

any idea what could be causing this?

and how to fix it?

Answer

The problem has been resolved by the Primefaces team (actually it seems like the bug has been previously fixed and resurfaced in later versions):

Official bug description

The fix is already available since version 3.5.9 for Primefaces Elite users (a subscription service with a monthly cost), and should be generally available when version 4.0 is released (which will be free and open source):

Primefaces Downloads

There is also a small discussion about this on the Primefaces Forum.

Edit: Since October 3 2013, this fix is available free as community release 4.0: Primefaces Blog