Hmm... I blew this one. However, MSDN does not support that "Also, sp_fulltext_database cannot (and should not) be used to enable/disable full-text search."

Cf. description of sp_fulltext_database at http://technet.microsoft.com/en-us/library/cc721269(SQL.100).aspx#_Toc202506258.

Seems funny that you can disable a feature but it still works.