as far as i know:
a Known limitation
is the correct answer,
However the meta data is still there but is not shown.
All of the meta, including which columns are shown in the vault view in Windows Explorer, is stored in the database. When you are working offline you are disconnected from the database so nothing shows up. We've told our users to export the data from the view into Excel while they are online so they can look in the Excel file for the information when they are offline. Of course this only works if they know beforehand which files they'll be working with.
EPDM 2011 SP2