Yep, exactly the same problem. Just posted: http://www.adobeforums.com/webx/.3bbaa316.3c05a9da
At least we know we are not alone !
I guess it is caused by the fact that when the file info panel is open all the top level menu items are disabled, but then our extra one does not get re-enabled when the panel is closed. Something I would have thought could be fixed quite easily ???!!