Installation of addon via unopkg.exe works flawlessly if it's installed locally
on a testserver (it's sure that there are nor running OOfice instances), the
extension shows up for all users.

Install string used in a batch is

       unopkg.exe add --shared HistoryMaster-1.0.3.oxt

When deploying the extention remotely using the very same batch, the extension
does *not* show up for any user.

This is strange because I even see the batch running on the screen if I'm logged
on via rdp. I also used "-v --log-file exension.log" but no errors are logged. I
also tried "unopkg.exe reinstall --shared org.bmarcelly.HistoryMaster", but
still no joy.

I contacted the extensions author, but he sais it's all strict basic and nothing
special.

Other extensions installed with the same batch are

   DisableFirstStartWzd_ooo31.oxt
   dict-de_DE-igerman98_2008-12-08.oxt
   sun-pdfimport.oxt

those extensions work fine and are also listed in the extension manager after
installation. The obvoius difference between the 3 working extensions and
History Master is, that the latter modifies the OOffice GUI.