MacMenubarPlugin does not work on Cog?

Hi. I am testing a Pharo image from here: https://pharo-ic.lille.inria.fr/hudson/job/Pharo%201.2/lastSuccessfulBuild/artifact/Pharo-1.2.zip

and the Mac host menu doesn't appear at all. I checked with

SmalltalkImage current listLoadedModules
SmalltalkImage current listBuiltinModules

and MacMenubarPlugin is included. However, evaluating "HostSystemMenusMacOSX new "   will throw a 'primDeleteMenu: failed'

Why the image doesn't throw any error???  Look in

HostSystemMenus >> startUp: resuming
    resuming ifFalse: [^self].
    self clearDefault.
    [self setDefaultMenuProxyClass] ifError: [].

So....indeed, setDefaultMenuProxyClass is throwing an error...but we are puting it under the carpet.

Anyway, does someone know why this is not working in Cog?  because In the standard VM in works perfect.

Cheers

Mariano